I think the temps are fine for a bunny...I've seen them being raised in outside cages where it snows. They've got great fur...but I'm sure the 'rescue' folks
can fill you in more. I've only had a temporary guest (abandoned-rescued) rabbit for a short time...my dogs went nuts, lol, & he was welcomed as a shared
pet in a convalescent hospital.
When I was younger my gram had “pet rabbits” for me that we raised in outside cages. Never did understand how those big rabbits always escaped and ran away, but the smaller ones never did.