Good luck with few minutes waiting if melten snow is coming fro sky and 10 minutes later you drive in area where temp is lower
You get your cars nose covered with 3-5mm ice.
Probably winter time they are not so usable. Better to keep at least small part always open. So if these grill shutters freeze, at least part of grill is open just-in-case. But then why bother with active grill shutters at all?
In winter we can just close 70-80% grill permanently and call it a day.