As Heidi suggested, my ex and I share Xmas day in the same place.
The DCs stayed here the first year, XH came round about 7am and stayed for lunch/afternoon. Dp came round with his DCs in the evening.
Last year DCs went to XH's house to sleep on 24th. I was at home in peace for Xmas eve, time to sort prezzies without having to wait until they were all asleep and I had some nice food and a good movie to keep me entertained.
They all opened stockings at his house then piled round here about 8am to open the big presents.
They got to spend the day with both of us and we were both on hand to help with building/batteries etc!
Not sure what the plan will be this year, but some variation on this theme.
We celebrate Xmas with DP and his DCs the weekend before 25th and he does the same, sharing the actual day with his ex and her family.
It's a bit shit knowing that he's playing happy families with the ex while I'm doing the same with mine, but I figure Christmas isn't about us, it's about making the DCs happy.
As there's no animosity between us it's possible that we'll talk the exes into sharing Xmas with all of us together one year, but it works pretty well as it is. I know this might not be possible where there are big issues with the ex, but where possible I think it's fairer than making the DCs leave all their new things behind to go to another house for half the day.