Buy the best outside heated cat shelter for winter: http://www.kosspa.com/heated-cat-house.
This house keeps up to 4 cats warm and comfy in cold temperatures.
A heated soft foam bed with a washable fleece cover uses just 40 watts of power o generate heat.
Dual exits allow multiple cats to come and go and prevent being trapped by predators.
Unlike other similar animal heating houses and shelters, A-frame design, durable nylon exterior with a waterproof fabric, and overhang roof keep your pet dry when raining.
There isn't anything more satisfying to outdoor cat than a warm, protected place like this heated house.