When you are going to sleep convince yourself that tomorrow isn't Christmas, then when you wake up at 5 am, you can just say, "Oh ya! It isnt Christmas!" Then you will fall asleep.
The other thing you can do is just read a book and wait for others to wake up. Or maybe you have a sibling who is willing to get up with you? Either way, don't panic! If you worry, it will make you sleep even longer! *BBBBZZZAAAT!*
KC8