I used my Kymco to commute to work here in Ohio for a few years.
With a clear forecast, and no salt on the roads - I set off for work that morning - mildly concerned about two things.
One - my corneas, since i like to keep my face shield cracked open a 1/2 inch when riding.
And two - the plastic of this scooter on this crazy ride.... "Am I going to hit a bump and this thing'll shatter under me like a glass bowl?!"
Well, my eyes survived and the panels didn't shatter.
Stig
While I was still working I was also commuting to work on my bike every day the roads were clear. A co-worker in my department would also ride 50 miles one way to work on his BMW for many years so that he and I were the only riders during the coldest days of the year. One year he stopped riding when it was cold so I asked him why. He said the plastic on his BMW was prone to the tabs breaking from being cold and brittle. I think it was more likely he had tried to do maintenance on his bike and broke the tabs taking those panels off. Yes, the cold does make the plastic panels stiffer and less flexible. But the plastic that is used to make body panels is VERY flexible to begin with, just less so in the cold. I've learned that if you don't pull off panels when they are cold then there is no problem. The normal shocks of riding will not be an issue. I've never had an issue with that since I started riding in sub-zeroF temps back in 2005. And all my bikes since 2001 were fully clothed in plastic (GW, Burgman 650, ST, CTX, Burgman 650, AK). Most years I'd be commuting several mornings at temps from -10F to -2F so I think if there would be a problem I'd have at least a few just from riding. I say there's no issue to worry about. Just avoid pulling off panels when they are cold.
As to your eyes...
Yeah, my eyes would tear up sometimes if I left my visor cracked open at near zeroF temps. I used to open my visor to avoid fogging due to the cold but from my co-worker I adopted an idea. I made a snorkel from a small nylon plumbing ribbed elbow and slipped on a short length of vinyl clear tube. I cut the clear tube to be right at the bottom edge of my full face helmet on one side and hold the elbow between my teeth on that side to hold it in place. I ONLY exhale through this snorkel and inhale through my nose while riding. This totally prevents fogging of my glasses and draws in fresh air as well. I have a Pin-Lock visor so that doesn't fog up anyway but that doesn't help my glasses. I rinse this snorkel out after every ride. Been using it for the last 10 years with great success. I almost never ride with my visor open any more when riding in the cold.