Teeki, in your circs, I'd do Christmas early or late, your DD is too little to know much difference - you get to spread the magic over a few days - BONUS!
We had to do this a couple of years back when our house got struck down with gastro at Christmas - i refused to allow anyone near us for a while, so we had our (sickly) Santa Christmas on the day, and then other stuff a couple of days later

Artechim - your six year old makes it difficult to do that sort of thing, especially with the Santa thing - is it possible to take some of their presents - something small and special they can use/play with while away, and some elaborate letter from Santa saying their other gifts are snuggled safely at home (and then make sure the kids are out the door before you or DH, and set up the presents to be waiting for you at home?). Maybe do the same thing with presents from you guys - take one each that is special, and leave the rest at home. perhaps one they open before they go, one on the day while away, and anything else when they get home? It would really depend on what you're getting them as to how that would work though (DD is getting some lego stuff - little things are easily transported, but big sets, no way!)