When you check out of CS, have them transfer your baggage to BWV. Then take a bus to one of the parks, grab a bus to BWV. Check in and you might get lucky and get a room right away. But, if not, then you're all checked in and you can call later to get your room number. Then go off to whatever park you want.
This is what we did last summer and it worked pretty well. We checked out of CR, they got our stuff to BWV, we went to BWV, checked in, went to Epcot for a few hours, then back to BWV to get our room. Worked really well.