We have had PS for CRT before opening - never at opening time itself. So I am unsure if you would be able to get in early. I hope you will, because - you are right - it is a great photo op. We had about 20-30 minutes one trip and got great video of Minnie and Chip and then Chip and Dale Dancing together on a completely empty Main Street. They all took pictures with our family. Another family that was walking in for PS also interacted with Chip (or was it Dale) and it was really fun to watch them chasing around after each other. We were able to get great photos of our family infront of the castle with NO ONE in the background. It was truly a magical morning.