Been there, was cool indeed! If you aren't planning to already, you should come to the 31c3 :)
Also WiFi totally rocked on day -1, but if you want that I guess you could also go wired any other day (symmetric gigabit and the best abuse policy in the world yay!).
But of course you can also travel on the day it starts and miss a few talks, it's up to you and your family how much of an issue it is to miss 2nd Christmas day. I was home in plenty of time for new year though, you still have that ;)