I'm in Ohio and started experiencing the limited regen on my model 3, coincidentally right after the v9 update (happened to be right as the weather was turning). After reading up on here about winters with a Tesla, I scheduled charging to start at 4 am every day.
Oddly, my regen is still limited some mornings. It seems to me that once the charging is complete, the model 3 keeps the batteries warm enough for full regen, but if it's still charging when I get in, regen may still be limited.
Anyone else have this experience?