Personally, I would spend the $20 to park at TTC instead of wasting time parking in the DS garage, walking to a bus stop, waiting for a resort bus and then taking the long ride from DS to either the Epcot Resorts or MK resorts (and then doing the reverse to get back to DS to get my car).
ETA: I'd park my car in the TCC lot and take the tram to TCC. Instead of the monorail, I would walk to the Poly from there. Then I'd monorail over to GF, followed by the CR. Once done at CR, I would walk over to the MK and grab the first bus I saw for one of the Epcot resorts. Visit the Epcot resorts and then take a bus back to MK. Take the ferry or monorail back to TCC, tram to your car and you're done! Twenty bucks spent for a full day of resort hopping and you never need to move your car once it has been parked.