If you cross-over at 1000 Islands, plot a route through Adirondack State Park and head over to Lake George NY area, it's an absolutely beautiful area. Lots to see and do. Check with Lake George Chamber of Commerce for their schedule when you might be in the area. Best RV park bar none..........
Lake George RV Park: Lake George New York RV Camping At Its Finest
For Vermont....check out the area around Stowe VT..... Home of Ben & Jerry's Ice Cream in Waterbury just down the road.........free ice cream with the tours........beautiful scenery in the area. Don't miss Smuggler's Notch.......but NOT with the travel trailer, tooooo skinny through the rock cut. Take time to tour Route 100 anywhere throughout Vermont.....voted one of 10 best scenic roads in the USA. Suggest Gold Brook Campground on Waterbury Road between Waterbury and Stowe.
New Hampshire...........central for camping in the area I suggest
Twin Mountain KOA372 New Hampshire 115 Twin Mountain, NH 03598
Be sure to check out local sites.......day trips to Franconia Notch, Mount Washington (highest mountain East of the Mississippi)(take the COG train to the top....or drive up if you're not afraid of heights), Conway NH.
You won't be disappointed!!!!!!!!!