For the ladies in your group, be sure to check out the bathrooms by the Village Haus--there be secret stalls there. Sort of.
When visiting the park years ago (8?), my wife went to relieve herself of her $3 Coke. Apparently there was a loooong line. However, a friendly castmember in the midst of cleaning the bathroom caught my wife's attention and pointed her to a completely different set of stalls that were completely EMPTY. Long lines for one set of stalls, drifting tumbleweeds for the other set. My wife dubbed these, The Secret Stalls.
Now I've questioned her on this many times, as I dont' see how a whole set of stalls can go unnoticed by most. She said they really aren't hidden or secret, but they ARE poorly labeled. I think she said that the bathroom is divided into two parts. There was a sign pointing to the less obvious half, but it was obscured by sinks or something like that. When you walk into a crowded restroom and see a line of people, you assume that's where you have to go--it's easy to overlook a different, less obvious part of the room.
The last time we went, she said that they had improved the signage and that part of the bathroom was getting more traffic than before, but it was still less busy than the other half.
*Shrugs* Being a lad, I've never gotten to see these mysterious secret stalls, so I don't know how hidden they really are. But my wife swears it's the best place to pee. Shhhh . . . keep it to yourself though. I don't want to get in trouble if she has to wait in line next time.