Hi there, Alexandra!
It's awfully tough to predict the difficulty of making a reservation anywhere at any time, except for peak vacation periods.
I think the demand for dining at
Cinderella's Royal Table might exceed the demand for makeovers at
The Pirates League, and that it might be easier to find a spot for the makeover than for a meal -- but that's my guess.
Make sure you call the Pirates League as early as possible when you know your travel dates; like Disney Dining, reservations for the Pirates League can be made 180 days in advance. And do prepare to be flexible. If you are willing to work around availability, you'll find lots more options available to you than if you keep yourself on a rigid timeline.
The Pirates League can be reached at (407) WDW-CREW.
Have a wonderful time!
See you later, celebrator,
-Deborah B.