Thank you very much for all the replies

And for those of you who were there on Christmas, how did you manage the Christmas tree gifts and Santa ( my kids still beleive in Santa)
I would appreciate any information. Thank you very much
This is a bit long winded... sorry but I thought it best to include everything so you can pick and choose what will work for you.
We haven't been at WDW for Christmas, but we did live on the other side of the world from family for 5-6 years so spent quite a few Christmases away from our home. (Our girls were between baby - 8yrs at the time)
When the girls wrote their initial letters to Santa, they let him know we wouldn't be at home on Christmas Eve, we'd be staying with Grandma in xxx. They then asked if Santa could please leave most of their presents at our home, and maybe deliver just a few things to them at Grandma's place, (because it is too hard to pack all the things in suitcases to bring home - these days with luggage charges it's just too expensive). They knew that their presents would be waiting for them at home when we returned after our Christmas vacation.
A few days before we left for our trip, the girls would write another quick note to Santa, reminding him of where they'd be, and their 'present drop off' request. They used to leave this note in their little stockings in our lounge room for one of Santas elves to pick up during the night .(You know, the ones who come around to check if you've been naughty or nice

). The elf who used to visit us was called "Barney" - how do we know??? He used to leave a letter for each of our girls in their stockings to replace the one he took for Santa.
Did our girls feel left out Christmas morning because they only had a couple of smaller, more easily transported things from Santa? Definately not. In fact it was almost like they had two Christmases, one on Christmas Day with the excitement of being in Aus with family, and another once we returned home.
This year we'll also be 1/2 way around the world for Christmas - (going to WDW for NYE shortly after) - and even though DDs will be quite a bit older (10 & 11) - no-one has mentioned they don't believe in Santa, so we put out our stockings, and Santa still comes - to me & DH as well. So once again, our old 'ritual' will be dusted off ready for Christmas.
Hope this helps you plan for your kids, we found it always helped to start talking about it way in advance, and in such a way that our DDs almost thought it was their idea, and so were much more excited about the trip, and the 'double Christmas from Santa'.
No matter how you decide to handle it, I'm sure you'll have a magical Christmas & NY in WDW. Cheers!