This summer my mom and I are planning a trip up the east coast. We are going to spend a few days in NYC visiting my sister, then we are thinking of going to Boston and drive to Bar Harbor to visit Acadia National Park. I hear the drive from Boston to Bar Harbor is 5 hours. If we drive, where would be a good place to break up the trip? I have read that it it not a scenic drive.

We have visited Boston and Portland before. I loved both cities, so I don't mind visiting them again.

Here are our options:
Fly from LGA to BOS and drive to Bar Harbor
Fly from LGA to Bangor and drive to Bar Harbor
Fly from Bangor to BOS

Any advice is appreciated.

MHT Manchester NH might be something to consider although not much closer if at all than Boston but would be an easier airport to navigate with a rental car.

Bangor would be closer but you would miss out on an interesting stop.

If you are interested in art, I suggest Rockland and a visit to the Farnsworth Art Museum. Maybe an easy hike out to Owls Head Light to stretch you legs. Or visit the sweet little Rockport harbor just north of Rockland.

If you get off I95 in Brunswick (college town) and take Rt 1 it will add 30-45 minutes to your drive but would be more scenic. Bath is location for Bath Iron Works which you can see from the bridge. Boothbay would be a detour but if you like gardens, Maine Coastal Gardens is lovely.

Assuming you would do an overnight if stop off took a lot of time.

A quicker stop would be a quick visit to Camden and a drive up the auto road for Mt Battie to enjoy to view overlooking Camden Harbor but Camden is even further north than Rockland.
Lincolnville is next and then the drive goes more inland and is pretty dull until Belfast and Searsport.