I've never done this myself, but certainly you could occupy your time quite nicely at the Disney resorts without ever stepping foot in a park. The first choice that comes to mind if you are so inclined is Fort Wilderness. That is a pretty self-contained resort area with plenty of recreation and entertainment choices including boat and bike rentals (horses too, I think), a petting zoo, swimming (though closing River Country was a HUGE mistake), campfires, storytelling, movies, etc. If you don't have an RV, you could always rent one, or stay in one of Disney's cabins.
As a Disney guest, you can enjoy all of the hotels - restaurants, entertainment, shopping, etc. But for a kick-back and relax trip, Fort Wilderness is great.
Steve