The early buses start running around 6:30-7:00, so getting to a character meal in a park isn't a big deal. If you have an 8:25 seating at CP, I would say be at the bus stop by 7:30ish. You may just hop on one, or you may just miss the previous bus...so you will want to be there early in order to not be rushed. Then you can just amble on into MK and down the street to CP...it's one of the really nice things about those early ADR's.