We did this last year from near Indianapolis.
Lots of other ways get you there, but this is what we did:
I-71 to Cleveland, then I90.
On the way out, we turned off at Erie and I 86 to 88 to Troy, then across southern Vermont and NH to Maine and took the 4 lane up to Acadia.
On the way back we went to near Boston for a few days, then back on MA2 etc. to Troy NY and took I-90 back across NY. Both the 86/88 and 90 routes work, with I-90 being a little quicker, smoother, and overall easier, I thought.
We did take US1 south out of the park area, partly because I'd ridden a bicycle from western Ohio to Nova Scotia when in college and wanted to see the big suspension bridge near Ellsworth again. It's been replaced (wah) but the replacement is magnificent (yay!)
Outbound overnights: Jackson Center,
Jamestown, NY at the Chautauqua KOA,
Pine Hollow Campground near Bennington (
http://www.pinehollowcamping.com) There was another Airstream there also headed east, and we really liked the campground.
Hadley's Point (
http://www.hadleyspoint.com) on Mt Desert Island. There is a free shuttle around the island, which we used and found convenient.
Also liked Hadley's Point. Can walk down to the water (it's a ways, but definitely walkable) and watch the tide come and go. Pretty cool.
Homeward bound overnights:
Minuteman Campground (
https://minutemancampground.com) which offered useful advice on how to take the light rail into Boston. Would definitely stay there again if in Boston area.
Delta Lake State Park (near Rome, NY
http://www.nysparks.com/parks/66/details.aspx) Pretty lake, some interesting historic sites nearby.
We also stayed at a place just east of Cleveland who's name I don't recall. Our oldest had a college visit at one of the universities there.
Route notes: 9 across southern Vermont goes up and over some hills, but it wasn't a big deal. We have 16' of trailer, and I wondered at the time how I would have felt with our previous 31'. OK, I thought, but not super comfortable.
2 across western MA is awesome. On a motorcycle, a Miata, or a Mini Cooper. It was fine for us, but the driver did have to concentrate. I don't think I would have liked it with the long trailer, but it was a no-brainer.
Stuff to do:
Chautauqua is tranquil. Lots of touristy stuff in the area.
Corning has Harris Hill, so if you've ever wanted to fly in a sailplane, that might be worth a stop. There are a number of wineries along the finger lakes as well.
Bennington was a surprise to us, but we hadn't really made a plan so everything was a surprise. Hemmings Motor News is headquartered there, as is Robert Frost's grave. All of us enjoyed it.
I enjoyed Newick's in NH (
http://www.newicks.com/index.html) But Mrs RedSHED just rolls her eyes. There is RV parking at Freeport, ME, but you'll want to look it up before you get there.
Acadia was a nice surprise.
Boston, duh, too much to see and do.
Cleveland has some nice art museums and some fun architecture around Case Western's campus.
I really don't have anything bad to say about any of the places we stayed. I was glad several times to have a shorter trailer and not to need full hookups, but neither of those would be strictly speaking necessary.
This is us, coming back through Troy, NY.
http://www.airforums.com/attachments.../8/troy_ny.png
You'll have a blast!