How do you avoid cold/heat death in Flax now?

Literally no place i can find on the calendar where i don’t lose crops to heat, cold, or even both in the same year.

Same! And it’s not just flax. I’m losing rye at an uncommon rate now. I have 3 fields with it growing at different times of year and I lose at least a third of every field every time to frost and then again to heat or drought. I’m also unfortunate enough to not have great environmental fertility (somewhere between 60-80%) to begin with so I’m already starting in the negative. The farming updates have made expanding with enough food very difficult now. All this and I’m playing in Idyllic Valley most of the time!