If you prefer Interstates, take a look at I-89 to Rt-101 thru Manchester, NH to Interstate 95. This would be the quickest route to ME.
If you prefer back roads head for NH Rts 302 & 112 thru Conway, NH on your way over to ME.
Obviously the foliage depends on when you're coming thru and many campgrounds close shortly after Columbus Day.
Formerly had 07 Neptune 36PDQ, ISB 325, Allison 2500, Source Trailing Arms and Ride Enhancement Kit, Demco KarKaddy 460SS.
Currently no Motorhome