You could take the commuter rail to Concord. Visit historical sites, walk to Walden Pond. I would check museum hours in advance, I believe many will close in late October for the season.

I would look down at the Cape (Cape Cod), there are a few all inclusive resorts out there that may fit the bill. I do suggest you try and rent some form of vehicle and take advantage of the falling leaves while you can. If you could swing it, there's plenty of things not far from you:

Salem is an excellent choice but try to avoid it during halloween if you can.

Fall River has Battleship Cove (The largest collection of naval museum ships in the US) and the Lizzie Borden House. I also suggest you try the Portuguese food while you're there.

Providence is train reachable and has excellent shopping, culture, and food. Make your way to Federal Hill and try out the Italian food if you can.

New Bedford has the whaling museum among other things. There's a ton to do before you get out of state, though it does get easier with your own wheels. It gets cold fast and the sun goes down earlier and earlier each day.