Making a Stray Cat Shelter

Two weeks ago we had an unexpected snowstorm. The snow melted in a day but it was a wake up call. I live in an area with a lot of abandoned, stray cats, and yes, we have been feeding them. The Humane Society is overrun with cats and won't take them in; they will be outdoors for the winter. We decided to try and make them some kind of winter shelter. We used materials we could get for free (boxes), materials that could be bought cheaply (space blankets - $1.00 at Dollarama), and Styrofoam packing and plastic wrap (which we already had).
First we made 3 box shelters - covered the boxes in the Styrofoam wrap (for insulation,
then covered that in heavy duty plastic (to keep them from getting wet),
and then with the space blanket to keep their body heat in.
We put carpet squares (bought a box of them at the local recycling centre for a buck) on the floor for comfort. My friend made the most expensive purchases which were self-heating blankets which were put on top of the carpet squares. She also bought a microwave disc which can be put under a blanket in the box and will give heat for up to 10 hours. This will be used when the temperature really drops far below zero.

Then we made the enclosure. There is a shed in the yard with an overhanging roof which made a natural place to set up the boxes. A very kind lady at the dog groomers gave us 2 bales of straw for insulation of our shelter. Thank you Lisa. We made a platform to set 2 boxes on and put the straw bales at the ends of the platform.

After that we put hooks in the side of the shed and hooked a heavy duty tarp over the whole thing.
Its not a pretty site, and until the first big snowstorm hits we won't really know how well it will hold up. But its already being used, so the cats know its there and we hope it will afford them enough protection when the worst of winter hits.

We enclosed one other area. On the back steps landing there is bench area with just enough space for one box. We put a sheet of wood over the benches, a tarp over the wood, and plastic all around the railing.
This box has been in use now for over a month by a pregnant cat. We are hoping to get her into the house and to a rescue shelter before she gives birth, but she is very vary of people and runs when she sees us. So for the time being, she just has a safer, warmer place to stay.