Cold weather shut off

By cold weather I am talking -15 Fahrenheit and colder...
When firing up the truck in the extreme cold after it has not been ran all night ~ it will fire just fine, rpm are higher than normal, then direct shut off. All electrical components are still functional at this time, the engine is just off. When I attempt to restart the motor it takes about 15 seconds of rolling over to once again fire. I have mitigated this by during the initial start in the morning I will hold my foot on the accelerator keeping rpm at approx 2000 for 3 or 4 min and it runs like a champ. If i do not hold the accelerator long enough it peters out sounfing as if the air fuel mixture may be incorrect (just a thought) The only issue is when it is -30ish it doesn't fire correctly. I can't blame it for disliking the harsh negatives. It is more of a nucience to have to sit in the cold truck holding my foot on the accelerator. Any ideas let me know.
2001 silverado 5.3 and I have mediocre engine specific knowledge.