This line caught my eye....
"We don't like being on someone else schedule"
If you make reservations, aren't you on your schedule?
School lets out mid June in NE so before that you should be fine without reservations. Earlier than that and you will have a lot of cool or cold spring days. I understand you like total fexibility but that can come at a cost of not being able to stay where you want.
One recommendation is Conscook Bay State Park in Maine - great place to watch the Bay of Fundy tital change.
Have a wonderful trip!
