Hmmm.. I could bring my Santa hat for my Shinji, along with a mini-hat for Pen-Pen. I did that at the beginning of the year for Ohayocon when it was snowing, but if I can dig it out in time I'll bring the hats for some X-mas fun.
If you want to hear some Christmas music during your Christmas-cosplay group, I'll be bringing my Eurobeat Christmas CD's, and will be playing them at the cosplay.com table gatherings on Friday and Saturday night.
So if you stop by then with your x-mas costumes & attire, the music will certainly be appropriate.