My experience with Night of a Thousand Wizards was that being nighttime didn't help a lot; it was still 80ish and very humid and they packed us all together (and I hear there were ultimately 1500+ of us or something) in a fairly small area for like an hour while they cleaned the park (I guess?) and set up the special food tables and all that were for us. You might have seen videos of some impromptu battles between some various cosplayers up on a stage - that was where they had packed us while we waited to be let out to do anything else. (So, beware that if you try to stay until closing, that they will kick you out with all the regular patrons and then you have to wait to be let back in to the special event.)

I brought full robes and sleeveless vest/jumper but only wore them inside the hotel. I forget what I was wearing at NoTW. Poor logospilgrim, I think she was wearing full robes all the time, you know how she does...