Christmas is an unusual time for business. We tend to put lots for extra pressure on ourselves with "false" (but real to us) deadlines of what we have to finish by Christmas.
These deadlines create a loss of perspective on what is important and what we are here for, more importantly and they also create an increase in stress and tension which leaves us exhausted before the Christmas break.
If you are leading a team then the impact is multiplied as stress contagion causes each person to add to the stress levels of others.
My suggestion for you (if it is not too late already) is to look at the Christmas business break as 2 Public Holidays back to back just like Easter. Then put your deadlines and goals for what you want to achieve before this mini break into perspective, just as you do with Easter.
Even with extended leave though to the New Year. It is still not a huge amount for time out of the office.
Are there any of the "stressed goals" you have set to achieve before Christmas which could be more usefully reset until end 2nd week in January when you are rested and clear headed and able to be more effective? If there are - then reset them and enjoy the holiday season a little more. Pass this message to the rest for your team so they too can reset their "false" deadlines, enjoy their Christmas break and reduce your overall team work stress levels.
When you come back after your break the phones will be quiet for a while and your email clutter will be down, so you will have more thinking and much more productive time your hands.