You can complain all you want, but this is a known fact of any battery: The colder they get the slower the chemical reaction inside and the lower the output of the battery. It's why your car with the weak battery won't start on the coldest morning of the winter. I've been skiing with phones from three different manufacturers and they all shut down when they got cold.
Ironically, Apple's updated code might actually help you by lowering the amount of energy your phone is trying to suck out of the battery and allowing it stay on longer. Somehow, I doubt that it'll change your mind.
Best advice: Keep the phone in a pocket where it's warmer.