Also, any device with an LCD screen should not be left out where it gets well below freezing. Cell phone, laptop, digital multi meter DMM, some chargers, voltage readout on battery pack, electric bike dashboard, etc...
Many of those things you use are properly sealed against the elements. Unfortunately, you cannot expect this for most of our bike hardware.
Our bike hardware also experiences thermal contraction and expansion, especially controllers and hub motors. When contracting in a humid environment, a motor and controller can suck it moisture, and it will just basically hang out inside all winter..
This happens to your car as well. It's why some exhaust pipes make pinging noises as the hot metal contracts, especially in the winter.
I do not have this problem because i live 4000 feet above sea level, but most people do not.