We did our Maine trip, going from SW Virginia to Bar Harbor several years ago. We took I-81 up and then hit I-84. I-84 was pretty rough and I am surprised nothing really shifted or was broken in the trailer.
We spent an overnight at the BriaLee Campground in Ashford, CT. It was 7-8 miles off of the interstate, but was a nice, quiet campground with lots of trees, lake, amenities and the kids really enjoyed it.
We went to and LOVE the Old Orchard Beach area and we stayed at the Ne're Beach Family Campground. It's old, quiet, right in town, across the street from the lobster pound and 3 blocks (walking distance) to downtown. It's about 1/2 the price of the larger campgrounds in the area. You are close to Portland and it makes a good day trip from OOB. Be sure to visit LL Bean.
We stayed at Narrows Too when we were in Bar Harbor. It had larger sites than many of the campgrounds and the waterfront sites were really nice.
2017 Ford F350 Crew Cab 6.7L 4x4 DRW