I hate the idea of doing this
BUT
we have two older dc (12&10) and two younger (toddler and baby) if the older two wake the younger two up in the middle of the night we will all be up and it will be a long miserable crabbit Christmas Day.
Dd1's birthday was 2 months ago and we were wakened up about 10 times between 2am and 5.50 when we finally gave in.
Feels wrong saying "don't dare come through till at least 6.30" but I'm tempted. Was not so bad in previous years but not now we have four of them to deal with all day with excitement tiredness and sugar rushes!