My suggestions are based in limiting your carbs even if you don't follow a low-carb diet- any amount of carb restraint will limit how much weight you'll gain during this season.
I won't go into depth too much, but instead focus on holiday season practical advice.
First, let's talk about alcohol. Instead of drinking lots of beer, try to have more shots, drinks mixed with diet pop, and wines and champagne that have a smaller g/l carb content. At LCBO stores here, most price labels for wines have the g/l carb content clearly displayed on there (bet you didn't know that eh?). This approach is guaranteed to keep you as close to your pre-season belt notch as possible.
Next, let's talk about food- both dining out and eating in. Almost every restaurant out there has some sort of meat and veggie or meat and salad combo. Chances are most dishes you'd pick in a restaurant (unless it's Italian or a sandwich place) have some combination of those three. Don't feel shy about leaving some of the fries, rice or what have you on the plate, as long as the meat and veggies are gone. Don't fill up on bread if the restaurant gives it away on every table. Skip the overpriced not-so-special restaurant desserts. You can apply this same mindset to dinners at home, except at home you can control the amount of rice, bread or potatoes on your plate, and you can also grab some dessert because it likely has less carbs than a restaurant dessert portion. Oh, and here's the most important part- resist the urge to eat disgusting late night foods after partying and drinking- try to make food ahead of time so when you get home you eat that instead of Chinese takeout portion good for three people lol.
My final bit of advice is not low-carb related but is going to help for sure and has to do with supplements. Holiday partying, drinking and dinners can mix in such a way that your body is starving for many essential vitamins and minerals. Sometimes, we feel hungry not because we didn't have enough calories in a day, but because we didn't get enough of our daily vitamins and minerals; or we did, but they got flushed out of our systems. If you don't have it already, grab an excellent multivitamin. Also, grab a pack of glutamine- a flavorless white powder supplement that, when taken on an empty stomach, helps maintain gut health even when you punish it a lot. Finally, if you don't take enough fiber, get a water-soluble fiber supplement- it'll help keep moving things along lol, and also help you feel fuller so you eat less.
There you have it, dearest readers- some practical, direct, timely advice on how to limit weight gain this holiday season while still enjoying what it has to offer. They are doable, so go ahead and do them :)