Hi, Maria!
It's wonderful to hear back from you! I'm such a big fan of
Mickey's Not-So-Scary Halloween Party and I just know you're going to have a great time at this special event! I'm really happy to hear that you plan to "dress up" for the party because I think it makes the whole experience so much more fun. And I absolutely love your choice of costumes!
For last year's Halloween Party I dressed as Maleficent, my favorite Disney villain. I have to admit that the headpiece (with those enormous horns!) got pretty hot and I ended up just wearing it for PhotoPass photos and for my special photo op with the Evil Fairy herself after the Villains Mix 'n Mingle Dance Party.
Central Florida in September is still rather hot. Evening temperatures typically remain in the 000. I think wearing boots may be fine, though I do recommend that they be comfortable enough for walking around Magic Kingdom the whole evening. As far as long sleeves go, it would really depend on the type and weight of the fabric used in the costumes. I would try to avoid heavy or non-breathable fabrics, if possible. If all else fails, instead of the classic Princess Leia white robe dress, you could always go dressed as Leia in the iconic outfit she wore during her capture by Jabba the Hutt in
Star Wars Episode VI: Return of the Jedi!
Wishing you a
hauntingly good time at Mickey's Not-So-Scary Halloween Party! Please let me know if I can assist you further with planning your upcoming visit. It would be my pleasure!