In the interest of preparedness concerning the cities along the East coast should a Megatsunami actually occur from a LaPalma landslide, where would be some the best places to go to get to high ground in a timely manner.
Here's a compilation of member comments taken from the main Cumbre Vieja volcano thread. I sorted member comments and organized by coastal state information regarding preferential routes, high ground places to go and tips for traveling routes. All coastal states listed. If blank, there were no comments provided for that area.

Hopefully, this list will never be needed.

AL:
In Alabama, considering the coastal areas which lie at a range of around 10-30 feet above sea level and Mobile Bay and delta areas, which are pretty low lying land areas, I’d say if it were possible, try to get to Mt. Cheaha area. It’s about 4-5 hours north of the Gulf Coast area and is around 1200-1500 feet above sea level.
You may not have to drive that far, to get to higher ground, but you’d need to take into consideration all of the rivers in your area and try to get away from those.

If anyone else from Alabama can chime in and give a closer point to get to than Cheaha, that would be great!
I agree with you, it depends on personal tolerance for risk. Dothan has the nuclear power plant, why I didn't include it. Birmingham is plenty safe.

By even the scariest estimates, Mt. Cheaha should be fine. Personally, I think Dothan, or even Atmore, would be far enough inland. I would be heading for Birmingham, elevation about 650 feet.

Pine Mountain near Columbus Ga is 1395 feet. The area is around 922 feet. Or go up 441 to the Appalachians.

Head North and West, maybe to the NW part of the state. Get away from the Mississippi River and the smaller rivers on the Northshore. No one knows how this would affect the Mississippi River, but I have a bad feeling about that.

CT:

DE:
Drive to Lancaster PA or on to Harrisburg if in DE
Those in Lower Slower Delaware will have to drive up the peninsula first.

FL:
NW out of the State. Can cut across the State to the W. Coast very easily and take backroads heading North once gridlock happens. You COULD take 95-N, but it follows the entire Eastern coastline. What if gridlock occurs before you can exit and head West? That’s why my immediate course of action will be to head West first. You need to evacuate the State and assess from somewhere that you KNOW will be safe, like Eastern TN or Western NC. You need to be ready for now panicking aggressive drivers and chaos once it all goes mainstream. 20 million people in this State. Early response and speed of reaction to the Event will save your life. Make sure you are armed, but don’t be paranoid, don’t cause any trouble or start any problems- just stay “switched on” and be on guard. Keep your personal space safe. People turn into animals when they are subject to fear or chaos, oftentimes resorting to violence for any number of reasons. Look to pre-landfall Hurricane behavior for an example…fighting in stores, robberies, thefts, driving recklessly, etc. This is the one time in my life where I will advocate speeding, but not beyond your capabilities to react suddenly. All eyes in the vehicle need to be either on the Road watching for hazards, clearing lanes for you to pass or using a mobile device to run reconnaissance on traffic ahead as well as plotting course while the GPS still works. 

FL panhandle, I’m headed 98 west to 77 north to 20 west to 331 north to Montgomery then I 65 north to safety. Probably if I can cross the bridges headed to families in Indiana. I’m 3.3 above sea and 1/2 a mile from the beach. I don’t know if this helps. But definitely my plan

80, 60, 27, 441, 98, 301 Fairly good roads, but not interstate. (Even numbered road, East/West. Odd: N/S)

GA:

I live in SE GA close to the FL border. My plan is to head NW to Waycross, then toward Macon of needed.

LA/MS:

Head North and West, maybe to the NW part of the state. Get away from the Mississippi River and the smaller rivers on the Northshore. No one knows how this would affect the Mississippi River, but I have a bad feeling about that.

Evacuating south Louisiana has historically proven to be a very difficult task due to stubborn citizens and slow-moving government officials.
Lake Pontchartrain gets surges from hurricane waters, and would most likely be affected by tsunami waters as well.

Jackson, MS, should be safe.

MD:
If on the Chesapeake region in Maryland you need to high tail north west to at least Fredrick, MD.

For Wash, DC - see below

NC:
BEFORE official EBS alerts go off need to hightail it inland via major traffic corridors before they become parking lots. Goal is to get west of I-95.
hurricane evac plans of reversing all major traffic corridors (like I-40, 795 64/264).
Both Carolinas are problematic due to low country, so many waterways emptying out into ocean. Depending on size of wave and amount of water being pushed, NC's OBX will be like front tackle line but then energy of water moves across the big Albemarle Sound and pushes up all rivers, creeks, etc.

Folks inland living on/near waterways need to factor in rising water and the backwash of debris once water reverses proper course to empty back down east.

NH:

NJ:
just take one of the many roads West toward PA.(195-95-PA turnpike route). Aside from NW Jersey where there are mountains, there's really no other option but to haul ass into PA.

In NJ, the safe counties would be Morris and Sussex in the northwest corner. (30 miles west off the GWB)
If you go into PA, stay away from the Delaware River because the water will come up it.
Keep an eye on traffic patterns. If I get the sense that the general population is starting to flee, I'll stop short of approaching the Delaware because getting stuck in a bottleneck (The Delaware Water Gap) there would be very bad.

NY:
There's the Pocono Mts (Seems a good choice with major hwy to get to it. See NJ for further info), Catskills(seems too close to coast) and Adirondacks (seems too far to try to get to)

PA:
Route 611 in eastern Pennsylvania rides the delaware river. Stay out of that area of travel. Easton PA floods often.
Note: the PA turnpike loosely follows the Appalachian Trail. Means one can leave the TP on foot and haul ass for the

Appalachian Trail (appalachiantrail.org) which is a very high elevation, but does not follow the turnpike. I know there's a hill just north of Lancaster/Manheim area that is 1,125 feet above sea level. Where as the TP near Manheim is about 500 feet above.

(paturnpike.com)
PA turnpike is low all the way to the west of Harrisburg. Be better to go up 81 either into NY or to 80 to go west in PA.

For Lancaster, the Mt. Gretna area is 1,050ft average. Just North of Manheim going to Lebanon.

MA:

RI:

SC:

TX:

If you are on Galveston Island, cross the causeway, take HWY 6 north, exit is very soon after crossing the bridge. This is to avoid Houston. If word gets out, Houston will be hell. Houston is hell during normal times.

VA:
For Wash, DC - see below

VT: Vermont (my home state) is most likely safe. Head toward any of the Ski areas, or Mt. Mansfield if close by

Washington, D.C.:

Here is flood map and elevation finder tools:
[link to www.floodmap.net (secure)]
[link to www.freemaptools.com (secure)]

Here is a topographic map to see where you are and where is the closest high ground:
[link to en-us.topographic-map.com (secure)]

Also, do have or print out paper maps.

Rule: Don't be scared. Be Prepared.