There are several options near, but not in, Woodstock. Kenneth Wilson State park, just a few miles west of Woodstock, is fairly inexpensive but probably doesn't have anything beyond a site with parking for an RV. If you want free with no facilities, there's a Walmart in Kingston, about 8 miles SE of Woodstock..
There are commercial campgrounds in Phoenicia (about 12 to 15 miles west) and Saugerties (about 8 miles NE, and right off the NY Thruway). In Phoenicia you'll find Sleepy Hollow and Black Bear campgrounds. In Saugerties there's Rip Van Winkle Campground and the Woodstock-Saugerties KOA.
24' isn't especially long, but I'd prefer to avoid driving into Woodstock proper with anything that's much wider than a full size van. Woodstock can get very crowded with cars and pedestrians, some of whom have the street awareness of a squirrel.
Thanks Steve, Kenneth Wilson it will be, and if full glad to have a Wal-mart close if needed. I love your squirrel analogy...but it's not just in Woodstock! Lol
Thanks, can't wait for our trip to see the fall foilage.