Maine Vacation

We like to stop in Freeport ME., the home of LL Bean. It's a nice town.
The last I knew they still allow overnighting in the town parking lot.
We also like the Sea Dog Brewery/Restaurant in Bangor.

Yarmouth, Maine has the world's largest globe -- Eartha. It is a fun stop, especially with kids, but won't take long.

L.L. Bean is an interesting stop.

Joyce

Boston has all sorts of stuff to see and do--many excellent museums, Old Ironsides and other historical sites, etc. You should have no trouble filling a day and a half. I've enjoyed the Museum of Fine Art and (though it's been a long time) the Science Museum and the Aquarium. The Van de Graf generator in the Science Museum is impressive.

If you like Mongolian barbecue/create your own stir fry sorts of places, Fire + Ice is quite decent, though a bit cramped.

Avoid if at all possible driving in Boston proper, doubly so with the trailer. It's not a fun city to attempt to navigate by surface street, to mention nothing of the fun of parking (and paying for the privilege). Public transit works well; the subway is not too hard to figure out. The tunnels in the area (which mainly means I-93 and I-90 under the city proper) do not permit propane. Apologies if you're already well aware of these things.

Your last day's drive home looks very long. I might think about splitting it up, and I don't mind fairly long drives. You know your own limits better than any of us.

Wells, Kennebunkport, Old Orchard Beach are all within about a half hour. You can stay in one place for three nights and see everything in that area. Ogunquit and Perkins Cove are nice but be aware it gets VERY busy in summer with bumper to bumper traffic at times.

I'm sure Acadia National Park is on your itinerary, but plan on a couple of days if you really want to see the park. Bike riding was fun on the carriage roads.

Doug

Botanical Gardens in Boothbay is beautiful.