I have never left the crate door open at night. We have always crated the pups until they were older. Keeps them out of trouble. We have witnessed him going into the crate on his own on occasion putting toys in there, taking toys out, laying down, etc. He seems to know it's his crate/bed. I suspect if I left the crate open at night he would likely lay on the floor by the door to make sure we didn't escape with out him knowing
I have sleep issues and if I wake up, I have a heck of a time going back to sleep, if I'm able to at all. I don't want him deciding it's play time at 2am.
My wife and I did discuss the fact that we will likely graduate him from the crate younger than most of our other dogs. Simply his size alone (16 weeks, 45 lbs).... And the fact he is a "wicked awesome" pup. (sorry, I have been talking to people from Boston this week). He has yet to damage anything other than a couple dog toys.