Depends on the timing when everyone else is leaving. Sometimes we would get right on a bus, sometimes we would have to wait for third bus. If park closing at 12am, there's probably parade at 11pm? There will probably be a bunch of people leaving after the parade, and another bunch at park close. Your bus wait will be less if you leave a little before midnight, or after midnight. On last trip, we hopped in 7DMT standby line at park close. The wait was short, then we took our time leaving the park. When we got out there, we were on the next bus.