Two years ago I lost a lot of trees due to a sudden cold snap that happened right at Christmas 2022. We hit 6F here on Christmas Eve - which is unheard of. It was my third winter here in NC and I got complacent - partly because I saw on the forecast that it was going to be followed almost immediately by seasonally warm weather (we hit 61F on December 30). I lost 41 trees. Many were small trees in development, but I lost a number of larger trees that I considered bulletproof - including a large Eastern Winged Elm that is native to this area. I did nothing to prepare for the cold other than move my Mediterranean species indoors for a night. I should have done a lot of things - which might in sum total taken a couple of hours at most. So it is "bonsai in haste, repent at leisure" for me - I spent the last two years regretting all the things that I might have done. The last two years I have shown and abundance of caution, and have not lost a tree to the cold
I should probably add that I don't as a rule worry about conifers. I have never (knock on wood) lost a conifer to the cold.