When our children were little, we frequently went to our parents for Christmas.... so... we had Christmas "early" .....
We did different things.... Santa came one time while I was giving baths to our little ones... and the oldest (maybe 4 at the time) was TERRIFIED! She was afraid to come downstairs because Santa had been there... (While I was upstairs giving the kids their bath, we heard Santa... "Ho, Ho, Ho"... and sleigh bells jingling.) We left the next morning, so there wasn't a problem with them telling other kids in the neighborhood that Santa had already been there.
Another time, when kids were older (and all but the youngest knew about "Santa"), we went out for dinner... and had the youngest go back and check for something in the house... (that way, he could see that nothing had been left by us to say that Santa had come...) by now, they all knew that if we were going to be out of town for Christmas, Santa came early.... anyway, we went out for a nice dinner, and guess what? Santa came while we were gone! (A neighbor came in and took care of putting out the presents, etc.)
That way we didn't have to take all the gifts with us, and they were usually receiving PLENTY at grandma and grandpa's houses to make up for the fact that they had to leave new things behind.
Anyway, that is what worked for us..... and it was fun!
Enjoy your trip!