You'd want to wait until the long-range forecast will be favorable for a while, when nights are well above freezing- that's why I'd wait, as long as he's not tearing himself
up. If you might be releasing him, do not handle him- it's safer for him if he's afraid of people. So for now (while you're deciding how he feels about being in a cage)
it's hands off...just try to read his body language, and don't get him used to eating f/t, btw. What are your daytime temperatures lately?