Mu family and I went to BoG two weeks after it opened in 2012 on a MVMCP night. We did not have party tickets, but we did have a 6pm reservation. We were nervous that there would not be enough time to eat in order to be out of the restaurant by 7pm when they close the park to the daytime guests. We were told it was fine as long as we didn't go to any of the party activities. We took our time eating, looked at all the rooms and got our picture with Beast. After 7, the restaurant was busy but not filled to capacity. (Maybe it might be easier to get a reservation on a party night!) We didn't leave until almost 8pm. We were paranoid we were going to get in trouble on our way to the exit. I bet if you didn't try to go into any of the shops, rides or other activities, you could wander around for a while.