I would def. try to stay on Mt Desert Island somewhere in SW Harbor or a rental overlooking Somes Sound because it would be less crowded/trafficky than Bar Harbor. But BH has lots of restaurants, boat tours, fudge shops, cute homes etc. so it wouldn't be TOO bad. We enjoyed a BYOB sunset tour of Frenchman's Bay on the Margaret Todd windjammer.
We stayed in a b&b on an inlet in Ellsworth because I wanted a central place from which to check out the Wooden Boat School in Brooklin, ME and the beautiful islandy area around Stonington, the gateway to Isle Au Haut.

We stayed at Acadia House Inn - LOVED it. Their food is amazing b/c they used to own a bakery/breakfast place.

You can walk from the Bar Harbor to a little island when the tide is out. The island has hiking trails. To get onto the sandbar, go to Bridge Street.

Agree with the recommendations for Southwest Harbor and using VRBO to find lodging. There are non-stop flights from National to Portland that are not terribly expensive if you book in advance (not sure what the far is at the last minute). It's about a three hour drive from Portland to Southwest Harbor, and about an hour from Bangor.

If the kids are into astronomy, take them to the astronomy talk on Mt. Cadillac at night. If they're still doing it. I loved it as a kid XX years ago.

You can fly into Bangor or Portland. Southwest is now flying from BWI to Portland. Bangor is much closer but if you have more time you can fly into Portland and do the whole coastal route 1 drive. It is a very scenic drive with lots of little coastal towns to stop and explore. Wiscasset, Rockland, Camden, etc.

looks at southwest harbor. a little drive from bar but far less crowded.

Lovely place. Great Food. Cheap Lobster. Crazy Tides. Love it. Go yearly b/c my FIL has a boat moored in near there during the summer. Love sailing...Love lobster. Hate sailing while avoiding lobster pots.

Oh wow, DH and I had a few wonderful vacations there pre-kids. Can't wait for them to get a little older.

We stayed in a rental home on a lake so I have no hotel recommendations, but now I might have to go hunt down the Lobster Truck for lunch!

We drove, and rented a lovely apartment on VRBO.

Acadia is amazing. Have fun!

We are looking into a long weekend trip to Bar Harbor, Maine - last minute. We are 2 adults and 2 young elementary age kids. Should we fly into Bangor? Suggestions on hotel/resort?

I want to see Acadia and generally spend time in nature.

Thanks in advance!