If all else fails, get together a "Nosey Bag" for Christmas Eve or morning when you aren't supposed to be up yet. When your family is still asleep, put on a dark blue/black outfit and sneak downstairs (map out a path which makes the least noise). In the Nosey Bag, there should be PJs, a dim flashlight, tape (to repair the wrapping paper after present-peeking), a plausible excuse as to why you're downstairs, such as "I had to get a drink of water and there are no more paper cups in the upstairs bathroom", and anything else you feel you might need.