I just got an alert on my phone for a freeze watch from the Mt. Holly station of the national weather service affecting most of us in in NJ and eastern PA.

Watch out!

Hi Dom
The first freezes are my best fiends.
They harden the end of year gowth wood, make the leaves leave the mother tree. and induce dormance.
Here zone 5 I allways let the plants outside with 1st frosts so when I hibernate them they are hardened and at sleeping stage,the last leaves that didn't fall by themselves I give them a litle push to strip them from the branches. 
It works good for me.

Thank you for sharing the warning.

snowing in central MA right now

I have one that still has it leaves. It's planted in a large pot. Is it ok to leave it out tonight here in SE PA? What would be the lowest temp that it can stand while in the pot?
Thanks!