I'd love to join

Same boat here

I would write it regardless, try not to get into your head about how it will affect your score. Get plenty of rest, do very light drills to keep your mind sharp, and get plenty of hydration. Neil Med Sinus Rinses will be your best friend, along with Nasal Steroid Sprays. Twice a day for both, the latter you can get through a family physician, but there are other weaker OTC ones as well. Rinse twice a day, once in the morning and once at night. These two will help clear your system. Write it, if the score isn't up to par (worse case scenario) cancel and rewrite on January. Not a huge deal either way.