This is the route that I have taken from Mount Pocono to Bar Harbor, Maine.
84E to 90E Sturbridge, Ma Spent the night at Thousand Trails, Sturbridge
90E to 495N, Boston Bypass
495N to 95N
95N to 395E, express way to U.S. Route 1A East
U.S. Route 1A east takes you to Ellsworth, Maine where you can connect to State Route 3 to Bar Harbor.
During my visit, I stayed at Narrows Too RV Resort. Thought the sites were more spacious than Mount Desert Narrows.
When do you plan on going during your trip? Also, if you have a dog, Bar Harbor is very pet friendly. Was able to take my dog into almost every shop.