How do I build a cover for feral cats?

These tyre beds would be cheap. Most tyre repairs will give you the old tyres.

Maybe something made from bales of straw with a plywood roof

Large Dog House. It will take a while for them to move in but it has worked for my brother's family. Couple of 2x4's cut to length for frame. Plywood sides. Slant the roof to let water run off. See if someone can give you a few shingles to cover roof. If not put a lot of outdoor latex all over. Renew paint each year. Throw in a couple of old pieces of clothing or fill with leaves or pine needles in the fall, for bedding. Before you start compare prices to a pre-made or one of those doggie-loo's

We purchased a large cooler at Walmart.

My husband cut out a small square near the right front corner. We filled it with clean dry straw. As added protection, I covered it with an old tarp.

I heard about the cooler idea,. Right now I have a litter box with a lid and a blanket in it and the cat sleeps in it. I tried straw but the cat won't go in with straw in the box It likes the litter box with the blanket. I'm just trying to figure something better before snow fall. I might get a storage bin that is bigger than the litter box and put the litter box in the storage bin and cut an opening in it.Cat seems to like the blanket in the litter box. They say that straw is better but kitty won't go in on the straw. Thank you so much for your response.