Just a word of warning. The parties that are way out from the holiday DO tend to be less attended. However, if you're going 9/14, that IS the first party of the year, and I would expect it to be fairly heavily attended, especially since they are starting later this year than in the past.
I don't say that to scare you, but so you can plan accordingly and adjust your expectations if that IS the case.
Aw, man.....
Do you think guest services the day of the party will have something posted about the where villains might be for pix and signatures?