Yes, we were there this past Saturday and Sunday. We stayed onsite, at Royal Pacific.
Both times, we were let into the park at 7:30 am.
On Saturday, we made it all the way through the park, into Hogsmeade, in the Hogwarts castle, and then held in the Griffendor common room until 8 am, when we were let onto the ride.
On Sunday, we did the same thing, but the ride was up and running and we got on at 7:50 and were done with FJ by 8 am.