Based on your itinerary, I'd say skip the RV. It will be more costly to drive and cumbersome logistically driving to/from campgrounds to sight see compared to hotels that are already in the areas you want. An RV as hotel on wheels will not be pleasant for that trip IMHO.
We finished a 10-day Boston/NH trip on Sunday. It takes us 2-days each way towing. We spent 4 nights @ Minuteman Campground and 3 nights at Lost River. It was a little less of a hassle for us since we tow a TT vs. driving a MH. Minuteman was a place to sleep. It could have been a rest area or Walmart parking lot honestly. Everyone was beat after each day we stayed there. We had two Boston city days and one beach day. Half a day on each end hanging out with friends near the campground. It was about 2h drive to Lost River where we spent only a little more time relaxing at the campground. We ate all breakfasts in the camper, but only two lunches and once dinner.