This is what we did for 6 months on the road. We weren't towing anything so when we needed to get groceries or wanted to explore, we made sure we picked a campground within Enterprise's pickup distance and rented from them.
Consider Aces High in East Lyme CT as your base. There's an Enterprise in New London.
As far as what to see
Mystic Seaport, New London CT
Take US 1 through coastal Rhode Island.
Cross Narragansett Bay at the Newport Bridge
Explore a Newport mansion
North to I-195, take US6 when you get east of Fairhaven MA
Several coastal towns along US6. This route also goes the entire length of Cape Cod.
Jerry & Jeanne
1996 Safari Sahara 3530 - 'White Tiger'
CAT 3126/Allison 6 speed/Magnum Chassis
2014 Equinox AWD / Blue Ox