I am from Canada so I know cold.
Ettore has the best rubber gloves for cold weather. Seal skin is a waste of time.
As for windshield washer fluid in your cleaning water.
Up here in Canada we have a washer fluid that has a detergent in it and is rated upto -45c it is green in color. This is the best stuff out there.
The regular blue stuff is not bad but requires a lot more soap and can really only be used as a 50/50 combo which is only good to about -10c.
Using any soap that has oxygen added to it makes cleaning easier and always use cold water. Hot water just is not a good idea.