Not nearly that cold. Typically low teens with an occasional dip into single digits. And mine is in covered, but not enclosed, storage. I am sure some of your northern neighbors will chime in on their cold weather experience.
Interesting info.
A fully charged battery has a freezing point around -80 °F while a discharged battery has a freezing point around 20 °F.
From this site.
https://www.batterysystems.net/winte...-storage-tips/