Sure, once in a great while for a night or two. But since 2016, when I purchased my house in Auburn, it was never a long enough cold spell to have a need to winterize. Even Death Valley can get below freezing once in a while. Death Valley hit -8°C / 17.6°F on January 19, 1928.
I used to live in South San Francisco, CA. I never bothered to winterize there either.
Usually, nice Decembers there. But it sure can get cold there in July! July can get a lot of fog.
"The coldest winter I ever spent was a summer in San Francisco.”
-Mark Twain. "
-Don- Reno, NV