You will be allowed in the park at 8 am, and should have no problem doing Dumbo, Winnie the Pooh, in fact most of Fastasyland and Buzz Lightyear and still be able to be at Crystal Palace at 9:25 (15 minutes prior to your PS). Grab a FP for something you want to ride after breakfast, and by the time you come back, you should be able to ride it!
Have a great time!