Cat House Simple. As simple as it is it should be able to stand up to the elements nicely. Pilot holes in opposite corners of each porthole and cut the holes with a jigsaw.
They love to play with the owners and can be found in the kitchen too to grab some milk or meat. So long as you have a couple cardboard boxes some tape a pair of scissors and marker lying around you. You should be able to find a quality cat house or tree for somewhere around 80 to 100 less if youre not worried about how attractive it looks.
Using the template draw the portholes on the front of the upper box and the back of the lower box.
The cats fur cannot provide such amount of temperature. Make a bunch of them to house the feral cats that stop by looking for a warm corner in freezing weather. Then use foam sheets to isolated the container. This is not the best option for insulation but it.