With a park to park ticket, can you hop back and forth as much as you want or just go from one park to the other one time?
As much as you want. We took the train back and forth a couple times,
As much as you want. You probably won’t do it too much. We usually spent most of the time in one park or another and didn’t flip back and forth much. You can either take the train or just walk.
yeah, it’s just one day, but I was thinking if I take advantage of the early admission to Harry Potter, go straight to that and do HP in both parks and then go back to do the other stuff.
Thanks!
that will work for sure.
You are staying there as I think that is the only way you can get in early.
Debating it 
Do it!!! SO WORTH IT
Park to park is great! Makes that last day in park a real value as you catch the rides you might have missed. And makes using the line wait app much more effective.