I have a 2 year old western Hermann's tortoise, so far I have kept him in an indoor inclosure since he was so young and little. I live in Michigan and I am wondering if I could put him in an outdoor enclosure for the summer. What is the lowest temperature he would be able to live in? I would bring him inside on the cooler days and nights. What would be the best type of enclosure if I am able to put him outside? Thank you!