I am planning 3+ weeks through Maine in September. First time I can travel after Labor Day when the crowds will be gone. I've camped many times in Maine but will visit new places there this time around. Acadia is a must but don't make that your northern most destination. It is quieter the further north you go up along the coast. The other piece of Acadia at Schoodic Point is a must. My favorite campground there is gone now, but I found a really nice one a bit further north in Harrington, Sunset Point. I'll be heading further north beyond that, several stops planned. Cobscook Bay State Park is one spot that looks wonderful. I don't have my list with me now of all of my plans but if you're interested I'll send you the route I'm taking and the parks I'll be stopping at, after much research. Good luck, and enjoy!