We stayed at Cape Cod Camping Resort in Falmouth, which I would recommend for a MoHo. We also stayed at Peters Pond and I would NOT recommend that place. It is mostly owners in their single wide's and they sprinkle campsites between them. The guy on the end couldn't stand us and was very territorial with his single wide. Nasty looks every time we went in and out. The kids go round and round in circles all day on the pond. Atlantic Oaks is further out and you could fit in there. A lot of Cg's close and a lot do not have FHU so call around. Though it is a drive as Cape Cod CG is in the beginning of the Cape, it worked for us as we drove back in forth. The cape also has the Rail Trail which is a bike trail laid out on the railroad runs. There are places to park, then you bike from town to town. That was a lot of fun.
In Woods Hole eat at Shuckers for the best Lobster Roll and shellfish. Woods Hole also has the Marthas Vineyard ferry for a day trip and inshore science excursions.
Nearby in Plymouth we just spent 5 days at Pinewood Lodge CG and I can only imagine how beautiful the lake would be in color. Plymouth just a quick 10 minute drive. Lots of restaurants historic attractions. We took the fast ferry to P Town which is the last town on Cape Cod, at the very end. Nice boat ride across the bay. Good food, attractions and shopping there. Also went whale watching which was amazing.
Not knowing your route, I would try to avoid I95 its just stress full and would stay north and take Mass Pike I90 to 495 to the Bourne Bridge. We also take I395 north south which is very enjoyable if you want to come south sooner. Then its a short hop on I95 to 195 to the Bourne Bridge. Hope this helps you
Happy Trails