Novia Scotia is always beautiful, and isn't that from New England. Unfortunately there is no longer a ferry from Portland (or anywhere in the US), but it could be a fun road trip.
I love Belize, particularly San Pedro/Ambergris Caye. It isn't far from the US, it has a little of everything (snorkeling, jungle, beaches, good food), everyone speaks both English and Spanish (and usually French Creole), and both local currency and the US dollar are accepted universally. It is incredibly peaceful, and except for the fire dept, there are no cars on the island, only golf carts and bicycles.
If you want to stay in the US, Telluride, CO is one of the most beautiful places on earth, especially in the summer. It is a place both with just mellow little boutiques and cafes and hardcore hiking and outdoor activities. Telluride is also about a 2 hour drive from Mesa Verde cliff dwellings and the four corners, so it makes a good day trip.
Where ever you go, have a wonderful trip!!