My poor neglected tent thanks you all! But seriously, its too much tent for me. My above post is exploring the fringe of where a system would fail, worst case, not at all the normal conditions. I was unclear:
As to snow fall: I wouldn't hope to wait out a 3-day blizzard in the Unishelter. That's an important clarification Paul and Kevin, thanks. 3' snow is the worst case, isolated scenario, and I would expect to wake up multiple times to shovel. Unrealistic?
That kind of snowfall pertained more to forested, sub-treeline areas (scenario #1), where the most snowfall I've ever seen in 10 hours was around 3 foot. Anytime I venture ABOVE treeline, alone, in winter, it is for shorter routes with an eye on the weather.
Loss of loft & condensation: I've definitely noticed this so far, but... Last winter in PA (not exactly Wyoming, I know), I went 4 nights below treeline with the above system, but using a vapr bivy and tarp. Daytime temps were as high as 35F, bringing sleet / wet snow, but nighttime temps were -5F to -10 every night. Ice on everything, sloshy snow, and I've never seen so much fog. My clothes were soaked, but even on night 4 I was too warm, bag half-unzipped, and clothes were drier by morning. Should I not expect anything like that kind of vapor transport from a Uni?
These are 'experiments', conducted within a few hours of home. With the Mk1, this setup would barely fit in a 5500in3 pack, and w/ consumables would push 50lbs. I'd prefer to wait on the weather. I just want to experience system failure close to safety before deciding when and in what conditions to draw that line.
Ground pads: With synthetics, which compress less than down, I think one can get away with ~slightly~ thinner pads. Maybe I'm skimping at the expense of overall efficiency, tho. I'll look into the pads.
Rich: Do you know of any good info sources about using vapor barrier clothing? Usable under softshell action-layers, sleep only, etc?
Kevin: Megamids. With synthetics, would you still suggest a vapr bivy? (I also considered a GoLite Hut + vapr bivy for sub-treeline, but thought a Uni might give me more above-treeline options. Maybe I should rethink that.) Is ID's silshelter really comparable to a BD megamid stability-wise?
Anyway, sorry for wordiness. Thanks for your time everyone!