This weekend's numbers were insane. ...
I don't know how to fix it... probably need a LOT more signage at the very least... They need to build more parking lots somewhere as well, obviously. Perhaps use Celebration city as a dedicated satellite parking lot, and advertise it as such. I know they were parking buses out there this weekend. Only problem is that they need a direct access route for the shuttles.
The answer is easy, as you point out: a dedicated entrance for shuttles, more satellite parking, and more buses.
The problem is getting people to know about it, understand it, and actually do it. We're Americans: we drive where we're going. We don't take the bus. We want our car
right there and available to us so that we can choose our own schedule, even if it adds three hours to the trip.
People aren't logical. I retired four years ago, so now I work for a regional banner of a very large grocery chain (one of the top three in the country). People got mad when we took out the self-check lanes, even though they're ridiculously slow; the customers are "doing something", so it feels faster. We know objectively that having someone bagging makes the total checkout time much faster, but everyone hates being the second cart in line; they'd rather we open another lane so that they can actively put their groceries on the belt, and bag their own, because it
feels faster, because they're doing something.
Same for driving: you can't convince people that being on that slow bus, making multiple stops, is faster.