I'm not sure but could be adapted I would think? there are lots of ways to make it warm and cosy, maybe others will be along with advice. You could ask in 'Cat Chat' section you may get more responses.
We adapted our potting shed for the ferals when we had the bad snow last year and it has glass but no opening windows. We cut a small hole out of the front so they can get in (we bought a cat flap but not fitted it yet!) and so we could keep the door shut. I put a couple of igloo beds in which they use, a larger bed and also a box. I have fleeces in them to keep them warm and our two regulars use it a alot.