Hi Jamie!
Avatar Flight of Passage is one of my favorite attractions in all of the
Walt Disney World Resort, so I completely understand why you wouldn't want to give up that
FastPass+ reservation, especially with the popularity of the attraction! Just remember that it will likely take you at least 20-30 minutes from the time you enter the FastPass+ queue to the time you exit the attraction.
Luckily, although Guests are generally advised to check in about 10 minutes before dessert parties are scheduled to begin, even if you arrive after it starts, you will not be penalized, your reservation will not be cancelled, and you will still be able to enjoy the remainder of your time at the party! That being said, you will have less time to enjoy your sweet treats.
Since your
Rivers of Light Dessert Party begins at 5:15 p.m., that is when Guests will be able to start dining on their tasty treats. The buffet will be available at that time and will stay open for about 50 minutes. Roughly 10-15 minutes before
Rivers of Light begins, you will be escorted to your reserved seating area.
Since you will not be penalized for being late, there is no reason to notify the Cast Members that you may arrive late. I do, however, suggest arriving as soon as possible so that you don't miss out on any of the scrumptious goodies!
Have a Great Big Beautiful Tomorrow!
-Lindsey N.