My girlfriend and I was there Yesterday, it's well worth it. I'm sure Dumbo will make it's appearance again. I heard if it's really windy, Dumbo doesn't appear because he's fragile in high winds but not sure. Today has been a nice weather so I'm sure he'll appear.
Well for me I got there in front of the castle about 8:00 PM so I would say about 1 hour and 25 minute wait, standing up all the time of course. Waiting while sitting on the floor gets my legs cramped.