Hmm, looks like you're resigned to having them over, so now it's about damage limitation.
Set boundaries - tell him / them an arrival time and a departure time. eg 12-3 or 1-4, and he can go to the local pub with them at departure time if he still wants to hang out with them.
Food and drink - buy in M&S sides, things ready to pop in the oven etc, buy mince pies and puds, couple of bottles of wine, one of bubbly, some soft drinks, and get him to pay for it. Not you. Or if that's too much, split it 1:5 with you paying for yourself and him for himself and his guests. Normally I'd say to split the cooking duties but being alone in the kitchen might be a good thing! Take a glass of wine with you and pop on some carols or music you like, and take a long time prepping the meal.
Hide the rest of your booze. When what you / he have provided specifically for this meal is gone, if they haven't brought anything, then it's off to the pub.
Xmas presents - leave that all to him, not your responsibility.
Before they arrive, remind him of the departure time and tell him he'll enjoy one on one time with them at the pub and you're looking forward to a quiet evening in your own home.
At departure time, stand up and start handing out coats, tell them how much their dad is looking forward to one on one time with them at the pub and wish them a happy new year. Then go and hold open the door.
Don't deviate! Don't let them see any pass-ag behaviour is getting to you. Be a gracious host, albeit with gritted teeth, but you can get through it if you know it's for a finite time, and you can clock-watch anticipating them gone.
Then depending how it went, tell DP on his return you are never having them in your house again. And have a serious think whether or not you want to continue the relationship.
Good luck..