I live in cold Switzerland and a family in my house with 3 little children has one of them. The car is always parked outside. They seem really happy with it and this was never mentioned as an issue.
"Cold" Switzerland? Hasn't been the case in years. Bielersee used to freeze over dozens of metres for weeks, it hasn't happened for at least five years if not height.
In terms of places that are even colder then Switzerland not many people live. And you can't just compare the Bielersee, there are these things called mountains where people go up to ski and it does get quite cold.