Plimouth plantation books up months in advance for Thanksgiving. East Bay Grill and Isaacs in Plymouth are both good, but known for seafood. I'm not sure they have traditional Thanksgiving dinners usually, but they might on Thanksgiving. Plymouth does get tourists around Thanksgiving so you might find a lot of restaurants in that area are already booked for Thanksgiving day unfortunately. The Fours in Norwell might do a Thanksgiving dinner special on Thanksgiving (it is not on the regular menu though). They have a comfort food kind of menu. It's sort of a sports bar/restaurant combo. It's not too far north of Plymouth. There's also the Strawberry Fair in Norwell - it's super cute in an old farm house kind of place and lots of home cooked comfort food. I don't know if it would be open on Thanksgiving or not.