My DD is in 1st grade in a parochial school and the official school policy is that they "discourage it, but if you must take your child out, you need to give the teachers at least 1 weeks notice". We took her out for a week in kindergarten and again in 1st grade. No problem at all, we were given homework ahead of time both times, though, and it is due the day back. The school policy states that any work not turned in your first day back will be graded with a 0.
It seems that just as with the public schools, every school has its own policy, and even then, they all enforce their policies to different levels. Best to just ask at the school and find out what they want you to do.
Have fun in December, we were there the 2nd week this past December and LOVED it!