We did our first Christmas last year for x7 adults, x2 other people's children and X4 our own (including 3 month old twins who were still breastfeed)! It is totally do-able and much less stressful than I'd anticipated.
We made gingerbread men/ Christmas shape biscuits for neighbours and also 'Christmas sugar' which was just nice demerara sugar in jam hard with few teaspoons of mixed spice, nutmeg etc and couple of sticks of cinnamon (leave a gap at top of jar so you can see sticks, looks very pretty), tie with crimbo ribbon and couple of pinches with instructions to put in coffee or hot chocolate ).
For meal, we didn't bother with stater, got Dad to bring a fish dish (his preference to turkey), hubby did meat (ham&turkey) and I did veg. We thought in advance about how many hobs/ pans we'd need and written down rough times to put stuff on which was mega helpful. Set table night before. Defo keep people out of kitchen, my dad was trying to take photos of us with steaming pans in our hand...not ideal. If beach is near, you may want to head back a touch before gps and your dd to give yourself a chance to prep more.
Depending on your family (we also have more kids) we also had a 'kick out' time where we'd politely told people we'd be happy to host until around 8:30, we wanted the house back and I was still doing night feeds so was shattered, otherwise they could have stayed for hours.
Oh, and finally, Let gps do dishes. I normally always say 'no, leave them, i'd rather spend time with you and do them later' but was shattered and wanted time with dc so let a couple of them do dishes so you don't have them to do that night.
Come 9ish, all kids were in bed, dishes were done and we'd all had a lush day. Enjoy.