First of all, it's a Halloween party, not a city council meeting... Would you rather look back on your pictures and remember: Wow! I can't believe I did that - I look like a dork but I had so much fun. Remember how I tried to get out of wearing that Alice costume? I'm glad I did it, that was a memorable night!
OR Oh yeah... that Halloween T-shirt. I had bought an Alice costume but I didn't wear it... (sigh)
And I know you're concerned about it being too early in the month, but I can't wait until Friday the 1st. I have a whole bag of Halloween decorations waiting to be put up, but DH won't let me until it's officially October.
I don't have any children, so I don't get to go trick or treating. And I don't know what it is about Florida... but they don't seem to get in the Halloween Spirit like they did back in Minnesota. I blame it on the "Bible Belt" theory and the fact that many people in my area are not from the US. I haven't had any trick or treaters at my house in the 4 years I've been here.

But, you have all inspired me - I'm going to beg my DH to go to
MNSSHP this year. (I swear sometimes he has given his inner child up for adoption). Wish me luck!
As far as feeling like a dork - don't worry about it. I worked in the luggage department at ASMovies, there were a lot of adults that got dressed up before heading off to MK. I saw a grown man dressed as Bear from Bear In the Big Blue House. Full six foot costume - waiting at the MK Bus Stop. No one working with me said "wow, look at that dork"... we all thought it was so cool that he was dressed up and that he looked great.
Last year at work on Halloween Day, I was at my computer and one of my managers came up behind me and was asking me to run a business report (normal requests)... I turned around and she was a huge M&M. It was great!