screen wash dont work tho below -3c for me window cleaning that is, does vodca 
Seriously though, if you use a decent screenwash, give it chance to work.
Have your applicator wetter than normal, so you`re not just putting a bit of solution on the window. A lesser volume of water will freeze before a greater one.
A tip- fill a small Fairy bottle with solution from your bucket, stick it in your pouch and keep using it to wet your applicator. Even squirt it onto the glass directly and get the water running down the window; it`s also less likely to freeze if it`s moving.
Oh, and don`t overdo the suds.