The weekend was an odd one. Early last week, the low temps were above freezing and it rained Monday overnight into Tuesday morning. Around my apartment, the snow had disappeared; was the snow still around in the woods of central Minnesota?
Yes, yes it was. But only barely. The snow that remained was crusty and supported a person's weight. Only in areas of shade underneath coniferous trees was the snow powdery. My mukluks never had a chance to get moist - there was never any snow to stick to them. It was all firmly frozen to the ground. To get enough snow to bury a pot of water, a few of my scouts had to chop up the remnants of a collapsed snow shelter.
I opted to sleep in my warmer mummy bag, and older Marmot Col that is rated to -20 and holds the rating quite nicely. The reasons were three fold: first, I was ill and did not want to risk a fitful night of sleep; second, I left my insulated pants at home by accident; and third, hindsight would show that the low temp Sunday morning was 2F, 6 degrees colder than my previous low. Although I slept comfortably, I did learn than I need more insulation underneath me than a single shortie Ridgerest - I was warm above me but I could feel cold seeping to my back. This was confirmed by the frozen shape of my sleeping pad on Sunday morning.
Once again I slept in my MK1 with another person - to mitigate the condensation inside the tent, I opened the door slightly but left the mesh intact. I did not adjust the roof vents. Because ventilation is the best method to remove minimize from an area, it was necessary to open the door. Previously, I kept the door closed and the tent was a load of condensation inside even though the temp only got to 8F. Both nights, the air was still.
The method worked well. There was minimal condensation inside the tent, except on the downward-facing edge of the poles. Next time, I not leave the mesh open and I should have even less condensation. Although I know it is out there, BPL has an excellent article on managing moisture inside shelters (another must-read: Condensation on different fabrics). Surprisingly, no-see um mesh significantly impairs a shelter's ability to manage condensation. I had read this previous to this weekend, but wanted to see the results first-hand in the winter.