Set alarms on your phone and pretend it's phone calls from work, a friend in need, etc. Go hide in there bathroom and take a ten minute break.
Do you have allies in the family? Make a pact to take turns. Get them to lure you away on a pretense. Go help clean the kitchen.
If you can't wiggle free, give yourself permission to switch off. You don't have to fight every battle, you don't need to set everything right. It's amazing how long you can keep a conversation going if all you do is repeat the last thing they said to you back at them but you raise your tone at the end to turn it into a question. Make plans on how to compensate yourself for enduring this shit. Pat yourself on the back for maintaining peace in the face of adversity.
Nothing bores people more than showing them "a funny video" on YouTube. Or some really boring vacation pictures. Or have a non-controversial topic of your own and stubbornly steer conversation that way. Tell a story with no point. If you're sitting in something comfy, like an armchair, pretend to fall asleep because you worked so hard. Praise the food and how good it was every time you're biting your tongue and you really want to say fuck you.
It's family, it's the holidays. I'm not saying you should swallow all bullshit. But raise the bar in the interest of family peace. And remember that folks will blame the loudmouths, the ones who raised their voice more than necessary, and not the quiet one for any fracas.
None of these strategies will work by themselves. It's the mix that does it. It's better to go into the situation looking at it like a game you play. Not like: fuck! Uncle Bob is going to annoy me again. You have your armor on and uncle Bob can't do shit.