Two replies ....
First, my guests were on their own for getting back. The reception ended at 8, we watched the fireworks at 9...afterwards, some enjoyed the BW and others went with us to PI, others went back to their hotels (via normal Disney transportation).
Second, for Allison--I made it pretty clear that if you weren't staying at a STOP, you had to get to one. No one had a problem with it--the only real issue was that I had people staying at all the epcot resorts...they all just walked over to the BW and got picked up there. Make it easy on yourself--they chose to go against the grain, they are on their own.