Sleep- Lack of it on a large scale can severely inhibit your ability to have fun and enjoy the holidays.  We are a nation of sleep deprived work junkies at the best of times and at the end of the holidays we are likely less rested than at the beginning.  A simple strategy is to take mini naps of about 15-20 minutes during the day.  Find a quiet, dark place in the house and just disappear for 20 minutes.  Trust me, people will hardly know you are gone and you can even claim a lengthy bathroom break as the excuse.  Lie flat on your back, close your eyes and take several deep breaths relaxing a different part of your body with each exhale.  It does not take much sensory deprivation to revitalize the brain and invigorate the body.  With a couple of these per day your awake time will be much more productive and enjoyable.  
 
Exercise- Redefine your definition of exercise as "outside activity" this holiday season.  You may not get your long bike ride in but you can easily get a good walk in with the family.  Or better yet pick an activity that you can all do outside in the snow rather than watching another movie.  Embrace the opportunity to try some different activities like skating, tobogganing (run everyone's sled up the hill and you'll get lots of thanks) or a good snowball fight!