the way that Sirius does Holiday Music traditionally is they turn three channels over to Christmas Music--- Ch. 2 Starlite, one of the Country channels, and Sirius Pops (which plays classical selections like Handel's Messiah, etc.).
usually this programming begins the day after Thanksgiving, if I'm not mistaken.
however, this might all change with the channel realignment.
I wonder if they are going to run the Country Christmas Music channel this year.