I plan ahead if I can, and try to practice damage control. In fact, when you plan it ahead of time, it's not cheating in my book. It's taking a break. As long as you're planning it, you're in control.

Since it's mainly the party you're thinking of, I'd stay LC during the day - honestly, you'll feel a lot better in the morning. The few times I've cheated early in the day, I'm whooped by early evening. At least if you wait until night time, you can just sleep it off and wake up with a fresh start.

Drink plenty of water, too, especially if there's going to be alcohol.

Happy Halloween!