We know now that people are going to get drunk at your Christmas party. You can’t prevent it, you can’t do anything about it but you need to learn how to handle people at the party who are more drunk than you and, perhaps most importantly, how to handle yourself if you have had a couple of drinks around people who might be quite senior or important in your company. You need to pace yourself and have a clear and sound strategy.
Eat. Eat plenty. Once you think you have eaten enough then have just a little bit more to eat. You are going some way to protecting yourself and your body against the massive influx of alcohol that is about to happen. Once there it is about knowing your limits, having just enough to have a good time and enjoying yourself at a chance to let your hair down at the end of a long year.