Hmm. In that case, I would keep what FPs you have on the 16th until after you've had the chance to see the wait time (maybe in the 30-60 minute range?) on that late night a couple days before. If you ride it then and have no need to go again with FP, then reschedule it for something else earlier in the day. Most things at MK are not hard to get just a day or two before.