NFT - Outdoor pets in the winter... a question

[Mephistopheles Janx]

Winter is coming... and I've never had an outdoor pet before.

Some of you might remember that we recently moved to the area around KC and are now living on acres. About a week after we moved in we had a black kitten show up that has adopted us and we care about a lot. He has been an outdoor cat this whole time but with this cold weather around the corner I have some concerns.

I built a little house for him that sits on our porch and is in a spot where rain and snow cannot get to it but I still have concerns that it will still be too cold for him out there. The house I built him has styrofoam insulation on both the walls, the rear, and two panels under the flooring.

Here is the house for context:



The other option I am considering is placing his house in the shop and just closing the door on him overnight and letting him back out in the morning. Not my favorite idea as I don't want to have to keep a litter box anywhere.

Have any of you kept a cat outdoors during the winter in Missouri or somewhere that gets equally cold and have thoughts on this?

TIA