I hope you've booked some Private Christmas Parties. It's like picking up money off the ground.
Every holiday has these and you need to be playing as many as you can. Those people who like your music, and can afford to put on big parties, can be very good for your career.
Pay attention. Even the guy who wants to put on a show so he can be a big shot is still paying you. So what if he gets a little full of himself and wants to make announcements during your breaks. When he goes long that's less time you have to play. You're still getting paid!
Oh, and here's a tip: schedule your finishing time at 11:00 instead of midnight. That way you have agreed upon pay and you can always play the extra hour for more money... and they'll always want the extra hour!
Put "Private Party" on your website calendar when these are scheduled. (Or even when they're not) It lets people know you do private parties and may get you some inquiries.
Since most of your regular gigs are Friday and Saturday, book as many weeknight "Specials" as you can. You may get to the point that instead of getting together to practice, you're getting together to do shows and making extra bank.
Private parties are some of the most intimate shows you can do and those people can be some of your best fans. Treat em' right and it will pay off for a long time.