The difference between cruise level temperatures (-56) and ground temps is that the systems are cold soaked on the ground after a prolonged shut down.
Hydraulic systems, prop seals, cable actuated controls, water tanks, galleys all have problems at very cold temps. Once the temps got into the -40 range we used to call it 'cold enough to freeze the nuts off a jeep'. Airplanes too.
Things like fuel pumps not running, fuel being close to the freeze point even before take off, pilots frozen to the seats (DON'T lick the controls!) were common. Frost on wings. Engines no start due ignition exciters/igniters failing.
On the piston engine transports its common to have oil heaters and bring the batteries indoors.
Another delay reason is the F/O being late because his POS
car didn't start.
Don't ask me how I know this.