Had anyone trued a windshield to protect from the cold ?
Not a windshield but bar mitts/pogies do wonders on the hands. On the seriously cold days a snowboard/ski helmet with ski goggles if necessary.
I had a universal bolt on windshield from a motor scooter I purchased used. It had brackets that bolted to 22.2 bars (it was on a Honda Ruckus) and I gave it away. At the time I didn't have a ebike but now I wish I would have had a chance to try it on my 'Runner. I also had bar muffs but really don't care for them personally. I always have trouble getting them air tight around mirror mounts, and my 'Runner has mirrors. Look for universal scooter windshields and make sure it bolts onto 22.2 handlebars. I forgot the name of the one that came on the Ruckus but it was nice and tall.
They have several in different sizes on Amazon. Some of them bolt to the mirrors and seem like they would not fit e-bikes, but others have universal mounts like the one I have linked below. It's only $28, so I may try it out for kicks!
https://amzn.to/2WSvITW
I asked the guy I got the Ruckus from and he said Slipstreamer Scoot series. The one he had bolted to the handlebars, and I remember the clamps having 22.2 stamped on them. I looked online now and all I can find is the mirror stalk mounting options. That Slipstreamer was nice quality. Didn't flex or chatter at 45mph and never did anything while being jumped over railroad tracks. Just gotta find one with handlebar mounts.
Well, I tried the one from Amazon. It seems to be an ok unit, but it absolutely will NOT work with the hardware provided. The clamps are too fat to go under the shifter. I mounted mine by borrowing the hardware from my rear foot pegs. It worked, but not as well as I wanted. You still get a lot of air that wraps around the windshield. I'd say it blocks about 65 to 70% of the air, which is ok, but it's not enough to wear just a normal bike helmet. I still have to wear my full face helmet, and if I have to wear that, then the windshield is redundant. The other downers are that it squeaks like Styrofoam, and the attachment hardware is not strong enough for anything but light use. for commuting it would be ok, but seems like it would break if I hopped a curb. The windshield itself is nice, and I was able to reposition my upper headlight so it works properly with the windshield in place, but I decided not to keep it. A photo of it installed is below.