Think through your calendar
Write onto your calendar all the holiday events from school, sports teams, church, work, friends and family. Check with everyone in your family to make sure these are events they want to attend or think are important.
Schedule in those activities your family wants to include in their holiday celebration, including time to decorate, see Christmas lights, bake, make gifts, read stories, etc.
Is what you have scheduled on your calendar going to allow everyone to get enough sleep and rest? If not, rethink things. Create margins and boundaries. Know your own limitations as well as those of your family members.
Schedule in some "breather dates" into your calendar. When someone invites you to do something else, you can say you have something already scheduled - it's true!