What's up Derek!??
Well, I don't think I would let him go until there was a bit of a warmer window of opportunity in the weather pattern. This would give the snake a better chance to find a suitable brumation spot rather than possibly getting caught in a place somewhere far less suitable where the temps might drop too much and too sudden.
If you google a ten day weather forecast you can choose a good time to do this.
Hope the snake does well bud,......
cheers, ~Doug
-----
"a snake in the grass is a GOOD thing" 
