I’ve been to minus 65 in the climate hanger at Eglin AFB. That’s cold enough.
Why does the AF need such a hanger? To ensure their aircraft will start at that temp?
Been there, done that. The big chamber can go up to 165 degrees.
The McKinley Climatic Laboratory was the brainchild of US Army Air Corps Colonel Ashely McKinley. He had been in command of cold weather operations in Alaska. He was transferred to Florida to oversee the design and construction.
The WWII lend-lease of aircraft to the Soviet Union showed the need for planes to operate in extreme cold.