You can apply for EZPASS online. We were originally in Maine, so when we moved to TN kept our EZPASS accts, and when we bought the motor home, added a motor home transponder right online and thru the mail. We use it for the tolls in NY, Mass, NH (and yes, you'll go thru the Hampton NH tolls before hitting the Maine toll in Kittery on I-95). If you are asking for a place to overnight, we stop at Ft Chiswell RV park in Max Meadows VA, Western RV park in Carlisle PA, Newburgh KOA in Plattekill, NY, then the last night we are at our destination. I believe they still have an overnight RV and dump station in Connecticut eastbound at Danbury rest area on I-84 if you are looking for a quick in and out.
(On edit: might want to avoid Tri-State campground at Matamoras, PA. It is right off I-84 in PA just before you cross into NY. It should be a handy stopping point, but it was pretty nasty when we stopped a few years back. From the highway, it doesn't seem to have improved since then. Others have stopped there and camped in their field with limited or no hook-ups and didn't seem to have a problem, but we won't go back.)