My friend Tim just got back from an expedition to Greenland. He's often off to the remote reaches of the fjords to take photos of calving fronts. Sometimes he camps with colleagues, sometimes they stay in a research station.
Despite what you might think, the temperature is mid teens in the day time but gets down close to zero at night. So he wears our merino. He swears to me he wore his yellow NBL for the full three week trip and only washed it once. Hopefully the pants (no photos of those) did him proud too... I won't ask if he wore them for 3 weeks straight! "Amazing" was the word he used most.
Sometimes, we're all so busy running and riding in our merino, I forget it's a good thermal layer too!
Thanks for the debug Tim.