A little late but since somebody suggested it: A winter holiday mix & match (this may not be applicable to all winter holidays and is admittedly made more with Christmas & New Year's in mind since that's what I know, though I'm trying to keep it fairly general for flexibility)
Things to fill up your character's belly during the holiday festivities:
A big home-cooked meal with lots of sides. Make sure they get a good portion of everything on their plate
Bubbly drinks, sparkling cider or champagne or whatever they prefer--probably on top of plenty of food
Lots of little snacks and hors d'oeuvres that don't seem like much on their own, but add up in your character's belly
A nice big mug of hot chocolate to warm them up, preferably topped with marshmallows and whipped cream
A bunch of snacks and candy they were gifted by friends, coworkers, etc. that they just can't stop nibbling at
Too many cookies, either ones they made themself or were given by others--or both
Adverse effects of overfullness:
A bulging tummy that not even their big cozy sweater can hide
A belly full of bubbles, perhaps from what they've been drinking or from chatting while eating, rumbling away and looking for an escape
A queasy stomach from too much sugar or fatty food, all surely a little heavier than what they usually eat
A food coma that's threatening to knock them out on the couch while the festivities go on around them--hope they weren't planning on staying up to see the new year
A second course or dessert that they're ill-prepared for, given how much they've already eaten
A thoroughly distended tummy that makes it difficult to bundle up once it's time to head out into the cold
A nice hot cup of peppermint tea. Hopefully they're not sick of peppermint yet
A bigger, cozier sweater--ideally ugly beyond belief--to better conceal their belly and give it some space to settle
A hot bath to relax in after the fun, both to warm up from the cold and to help soothe their sore tummy
A gentle belly rub, hopefully out of sight of whoever else was at the get-together
Laying down or sitting back somewhere, trying not to draw too much attention to their belly as they attempt to digest
A heating pad to soothe their aching tummy, which they can play off as keeping the cold away if they want