we use rugs on all of our girls. They're called 'PRESTIGE Cosy-Fleece Dog Vests', but they can be hard to find. I bought the last ones off the net. They're great because they have a zipper on the back, and hug quite nicely to keep the dog warm. I also have some other ones that I use sometimes, but can't remember their names.

In the kennel, we use cheap rugs from the opshop (or kmart), and try to put our smell on them before putting them in the kennel. But it doesn't take much to get the girls into the kennel on a cold night!