My impression is that the Bibbidi Bobbidi Boutique is pretty booked up most of the time (you mentioned you can't get a later time.) There are just too many variables when flying into MCO to book any non-cancellable offerings. Not sure how close your arrival time to reservation time is--anything less than 3-4 hours is risky. If you're prepared to catch a cab or uber direct from the airport to DS you could consider that, but then you've got luggage to deal with. It never seems like it should take long to get from MCO to property, but somehow times flies by from point A to point B.