Saving the dog Busya from the frost

I bought a bale of straw for Busya. A bale costs $13. We put this straw in the dog's kennel. When frost starts, we put half a bale in the dog's kennel. Then, when winter comes, we lay down the second half of the straw. We don't put all the straw down at once. Because Busya climbs out of the doghouse and pulls out some of the straw with a chain. Therefore, we need to put new straw in the doghouse from time to time.