Power windows very slow or inop with cold weather

[Woowagon]

As the title says, the power windows in my 2000 Nubi wagon are very slow or just don't work at all now that it is cold here. I thought I had found the problem last spring (switch/wire contacts corroded) and they have worked great until now.

The slow/inoperative symptom is exactly like last winter. Anyone else have this happen? What was your fix? I am going to try spray silicone lubricant (the type that dries "invisible") along the window edges in the window tracks to see if that lessens the load on the motors but I think that is a long shot.