Hubby and I would like to take a spur of the minute trip to Martha's Vineyard. We would leave Michigan with our truck and travel trailer and camp somewhere near the ferry. We would like to take a day trip and I cannot do a lot of walking (due to bad knees). We are looking for suggestions of a nice campground in the area and then any tours that show us all of the major things to see on Martha's Vineyard. Is it possible to go in May and expect to find a site in a campground without reservations? Any help at all would be appreciated. Thanks in advance.