OP, look into some of the more remote towns on MDI (Mount Desert Island) like Southwest Harbor or NorthEast Harbor. You may find lodging there for a bit and there are plenty of places to eat and drink. You'll have access to Bar Harbor which can get a bit crowded although, as mentioned above, it's an off year for that area. There's really no reason you cant enjoy them all. There's a terrific museum there called Seal Harbor Museum which has one of the country's foremost collection of original, one-off types of antique cars including the first Stanley Steamer. For a quiet, traditional Maine setting, however, you'll have a hard time beating SouthWest Harbor.
Other than that, you might look even further North up to Lubec although I don't think there's much of a nightlife up there yet.