K-9 Voyager makes fantastic boots, they go over the knee. You will have to order on line. It may take some getting used to, but needed for these kinds of temps. Muk-Luks work also, but do not go as high on the leg, many pet stores carry them. Good luck. I'm in Wi. also, I feel your pain, I have 3 greys and putting 12 boots on 5 times a day is rough. So looking forward to the weekend so we can go for a real walk!
Jaime L