On another thread I suggested the Kancamagus Highway in New Hampshire. They generally have at least 2 campgrounds open year round. http://www.kancamagushighway.com/campgrounds/blackberry_crossing.htm
Which RV rental company allows picking up in NYC and dropping off in Boston?
The campsites on the Kancamagus Highway are about $18 per night.

For all your RV related questions go to the forums on RV.net.

To check for campground availability go to reserveamerica.com.

To look at reviews of campgrounds go to rvparkreviews.com.

Have fun!

For whale watching I'd go to Provincetown on Cape Cod. This campground is open in April -
http://www.abcamping.com/abcapecod/campsites.php

Another idea of where to go if it's colder north = the Amish countryside around Lancaster PA. Here's a list of campground options
http://www.padutchcountry.com/lodging/lancaster-campgrounds.asp

You should also realize that besides being chilly the countryside won;t be very attractive. Our trees don;t leaf until end of April or early May in NYC - and can be later farther north. Grass may still be brownish and there will be few flowers. For the outdoors to be attractive you really need to wait until early May. (Many sights may still be on off season hours - some open only weekends.)

Oh and you can;t drive an RV into Manhattan or central Boston - roads are too narrow and definitely no place to park it. The closest RV park I know to Manhattan is in Jersey and costsa bout $80 per night -= plus yuo have to pay for public transit into/out of the city.

I feel so sorry for this o.p. I hope you're not ripping each other apart over dinner over this!

Where are you first picking up the R.V.? Can you start your trip outside of NYC and head South instead of North?

Perhaps take your R.V. to the Outer Banks or Maryland for the week? It's sure to be warm there and quite lovely!

You could find an R.V. park in Maryland and visit Washington, D.C. for a few days.

April is a beautiful month for the southern part of the East Coast.

Bowsprit, what a great suggestion!

Every year my hubby and I do a 4-5 day trip to the Mid-Atlantic in April. You're right. The weather there in April is reliably better than ours on the Cape.

One of my favorite parts of the drive south from Massachusetts to Delaware/Maryland/Virginia is watching spring approach. Every 100 miles or so, you can feel the air getting warmer and you see more and more trees and flowers in bloom. It's such a welcome sight for us winter-weary New Englanders!

Washington DC and the surrounding area is well worth visiting. I'd spend a day or two there - although not quite sure how to accomplish that with an RV. (Maybe someone else can chime in with suggestions.)

And after visiting the DC area, I'd head straight for the "Eastern Shore" of Maryland and Virginia, specifically to Chincoteague Island and Assateague Island.

The Eastern Shore is about 3 1/2 hours away from Washington DC, and it's whole different world. Rural, laid back and absolutely beautiful.

In addition to visiting the Assateague Island National Seashore and seeing the wild ponies (a must-do!), there is plenty for families to see and do in that area. Lighthouse tours, museums, fishing, crabbing, boat tours, nature hikes, etc.

I've never camped there, but I know there are a number of campgrounds and RV parks that should suit the o.p.'s needs.

I also know there is some dolphin and whale watching off the eastern coast of MD and VA - just not sure about the time of year. With the warm winter and water temps we've had this year, the whales might have migrated farther north by then. Calls or emails to the state Visitors Bureaus in MD and VA would be a good place to find that out.

Yuo may well expect snow in the higher latitudes and elevations in New England in April. There will be no leaves or much grass. It is known locally as "mud season" or the "Fifth Season".

Mid-late April is the garden season in Washington DC and Virginia. Azaleas will be in bloom. The coast will be fine. But in normally RV friendly places like the Blue Ridge Parkway, it will still be wintry. I have experienced snow on May 1 at Peaks of Otter in Vrginia.

If you can possibly get out of your RV rental contract, please do so. Also be aware that the Boston Marathon on April 16 will impact lodging availability in Boston for the preceding weekend.

Ackislander: If they stay South and East they have little chance of encountering snow in the second week of April but of course anything's possible I suppose.

If you're set on visiting NYC, Boston, Cape Cod, etc. perhaps ditching the R.V. is the most sensible solution and renting a mini-van with a small television for the kids makes the most sense. Boston and NYC can be quite lovely in April. The Cape is always wonderful, it just won't be beach weather by any means.

Re. visiting D.C. with an R.V.: I wouldn't. However, if you're stuck with it, how about parking your R.V. somewhere in Maryland nearby (check one of the resources given above) and then renting a car or use public transport to get into D.C. proper? Would that work? I think you could have a great trip, just not the trip you've planned!

Your guide to RV parks on Cape Cod: http://www.elmonterv.com/guide/rv-campgrounds/cape-cod-ma-rv-campgrounds/
Enjoy your time at the ocean where it rarely snows in April.

The above is an ad. I'm not sure how helpful an RV company in south Florida would be in planning a trip to the NE.

Hi, have you tried www.koa.com and http://www.trailerlifedirectory.com/Default.aspx

You can also stay overnight in some of the walmart car parks for free. Useful if you are on the way somewhere.