Winterizing outdoor cage/hutch

Question
How can I get my guinea pigs outdoor hutch ready for winter? We got them in the spring and we've kept them outside, as I have an allergy to them. I'm on claritin for allergies, and we purchased an indoor cage to try it out.Unfortunetly, I still seem to have this allergy problem. Now, I'm worried that I won't be able to bring them in when it gets cold. Also, if you have any suggestions on dealing with the allergy, I'd really apreciate it.

Answer
Have you read http://www.cavyspirit.com/allergies.htm ?

Are you allergic to the hay or bedding? Playing around with different types may help. Also air filters.

I don't house any of my pets outside, so I can't help you there, but you could try an insulated shed.