Want to see how oil flows at -40?
 

Rich put bottles of Mobil 1 20w-50 and 5w0-30 outside for a few hours. The results I'd say are are expected. Even the 5w-30 thicken ups quite a bit, but 20w-50 is practically cold honey!

https://youtu.be/B-sPl_zpAtQ?si=HvGsO6JsnuOYKSyd

Can you imagine what it was like prior to multi-viscosity oil? That's the main reason Pontiac initially used reverse-flow cooling in their V8- to allow transfer of heat from the cylinder heads to the cold bottom end.

Also why 0W-6, 0W-10 and 20 are pretty much standard issue now on modern gas engines. The tiny orifices oil has to travel through for chain tensioners, variable valve timing features and cylinder de-activation systems would never work in cold climate conditions. Running one of these new engines with 10W-30 oil or heavier will almost guarantee a check engine light and dozens of trouble codes. Most of those internal passages are .007"-.015" diameter.

Yep, Red Deer, Alberta. Halfway between Edmonton to the north, and Calgary to the south. When I lived there, it went down to -40 regularly, and no one even mentioned it. By the way, -40 is where Celcius and Fahrenheit meet.