Kid #1 made a cat shelter for her barn cats out of a big plastic tote, insulated with cardboard and lined with a space blanket, with a flap to keep the wind out. She gave us a couple of pieces of the leftover liner to see if our girls will like it to reflect their heat when they go to their respective nests. (Fela has developed a fondness for sleeping on a clean furnace filter of all things; ALHS has gotten her to move onto an old thick quilt folded several times--very cushy.) Of course, both have nice plush cat beds that Santa brought last year; only Little Cat uses hers.
As to Kid #1's barn cats, they love the EZ Bake Cat Oven, as she calls it--it gets SO warm when they use it!
ETA: as I was putting the turkey breast into the crock pot last night, to cook this morning, Fela arose from the dead (or a similarly deep sleep) in the basement, came upstairs, and immediately came to the kitchen with her tail straight up and stiff, sniffing the air. Talk about a good sense of smell!