Kotared: I add winshield washer fluid (any brand as long as it says "anti-freeze") after inside work. As for amounts, I keep adding until my solution stops freezing on the wand or window.
Total Vision: See above and Glacier Gloves are great but you lose "feel" for the work. Seal Skins are great but once they're wet, don't seem to keep as warm. Any good window washing supplier carries a selection of winter gloves.
You really need to count on productivity dropping during cold weather. During winter months, I don't schedule any outside work 'till after noon.