Thanks you guys. Here in San Diego we dont get the 37 temp or less but good to know if I ever move back east.

A certified repair place put a new (BMW recommended) battery in last year. I will look into the alternator too!

Oddly, while driving just after posting my thread/question, I was reminded of another quirk when the radio sound turned off for several seconds (but orange power light remained on) then powered back up. This was another thing that I forgot to add earlier.

Maybe further supports the alternator theory. Thx!