Stop in for a cup of coffee

On bright side you were still below tree line! Pee in canteen cup so you don’t have go outside in middle of the night, rinse it with some snow in morning and sip coffee out of it!

Worst trip was survival training in Northern Quebec province... they didn't have much snow and it was a touch colder than usual that year so building shelters was a PITA.. Suck-factor was high.