I would totally do this!!!
I would have loved that as a kid! I remember one year I was going to try to see if it was my parents eating the Christmas cookies or if there really was a Santa. We were going out of town for the holiday, but I still insisted to leave Santa and his reindeer something just in case he forgot I wasn't going to be there. I made sure I was the last one out of the house so my parents couldn't do any last minute munching. Sure enough, the cookies had been nibbled and I still don't know how my parents did it...then again...I was only 7 and probably had the short attention span that all kids do at that age and they snuck back in before we drove off. I love Christmas memories!