Not knowing where your starting from this may or may not help. We make the trip from southern points to our home in Maine a number of times per year we avoid I95 like the plaque. We take I 84 to Newburg NY, pick up I 87 to Mass Pike, when we're in the Phoenix, in the car we will stay on 84 to the Mass Pike. Driving though southern Conn. and Hartford, can be miserable, with lots of traffic and numerous lane changes. The Mass Pike route is more expensive with tolls and an extra 100 miles or so but in our estimation well worth it. From our experience there are also better camping locations with this route, although I am sure there are good spots to be found. If you take the Mass pike all of our GPS' try to exit us in Worcester, which can again put you into heavy traffic. Stay on for another 10 miles or so and exit on I 495 ( try to avoid 495 during the commuting hours) This is where you would end up if you went (and survived taking 95). From this point on its 95, NH and Maine turn pikes. Here you have a choice of getting off on route 1 in Brunswick or going on and picking up route 3 around Agusta. As we live in the Camden Rockland area so we always get off at one of the Brunswick exits. Route 1 to route 3 in Bucksport which takes you to Ellsworth and follow the signs from there.
We just got back from Virginia taking the Hartfofd route this week and encounted no problems. We were also at Acadia a few weeks ago. Sites are nice, although ours required a bit of leveling, as do a number of them. Their saying our foliage is running late by at lesat a week, so not telling just how colorful it will be here. In addition to all the great things in the Park the Canadian Maritimes are a relatively short drive away We always enjoy Campobello and Roosevelts home, if interested remember a passport is necessary. Hope this helps, and feel free to ask for more information.
Enjoy your trip