Hi Samantha! Mickey's Not-So-Scary Halloween Party is so much fun -- you're going to love it! My son had an evening makeover at
The Pirates League during the Halloween Party last year, which I booked several months in advance, so you should be able to make a late appointment at The Pirates League now. It's possible that you're not finding available times because it's all booked up -- The Pirates League is very popular during the Halloween Party. Keep calling because people do cancel reservations -- last year I was able to call and change my reservation time, although it took me several tries before one became available.
If you have park tickets and are planning to visit the Magic Kingdom earlier that day, I would recommend you visit The Pirates League before the Halloween Party begins. The Pirates League was extremely busy during the party last year. My family had to wait quite a bit for my son's turn for a makeover. The pirate who transformed him was really funny, and my husband and I couldn't stop laughing at his antics, but we did miss an hour or more of the Halloween Party festivities while we waited for my son's makeover. In retrospect, I wish we'd scheduled his appointment earlier in the afternoon so we would have had more time to enjoy the Party.
Have a magical vacation! Come visit us again at the Moms Panel if you have more questions! We're happy to help!