What happens to an engine during a cold start in sub-zero temperatures?

Sorry to burst you bubbles but I've actually lived in South Dakota for 5 years. -20 too many times to count. Mopars worked fine. As a matter of fact I still have one 273 with 300,000 miles on it and it still starts and runs like new. It was run every day, summer and winter, all 5 years. When it got really cold, it was the only car that would start. So much BS to be flung to what end? The wild thing was the 90 wt Gear oil in the 4 speed trans at -20. It still works fine also.