As a divorce lawyer and custody attorney I meet people at some of the most difficult times of their lives. The emotions are raging, the anxiety is high and the uncertainty of cost, duration and results can make the best and kindest person become antagonistic and oppositional.
To protect your children from the worst that divorce or a custody disagreement entails, it is so important to work out ahead of time the schedule of when the children will be with each parent. Resolve the custody schedule for Christmas Eve, Christmas Day, Hanukkah, New Year's Eve, New Year's Day and the school recess.
Assume that the other parent wants just as much to be with the children and then decide how to allocate the time fairly. Perhaps take into consideration how the time was spent last year if the case has been going on that long and do the opposite schedule this year. Don't assume that the children should only wake up on Christmas morning in one home. The children know Santa goes to many, many homes. Consider the ages of your children and what time of day/evening they will be transported. Consider how each family celebrates the holidays.
Let the children feel loved in both homes and allow them to celebrate or enjoy time with both parents. If you can do these things, your children will remember the holidays fondly rather than as the holiday that the police were talking to their parents.