The road to not caring

[Spirou003]

(...) Combine a decent long lined skirt, or skirt with slip built-in; and your own half slip and decent socks, you are as well armored as with any pants. (...)

I don't think so. Roughly 15 years ago, I had a winter pant so warm that I could deal with -20°C without any other layer - save for feets and upper part of my body. I quickly took as an habit to wear a second pant under so that I could remove the brutally hot winter pant when entering in a building. I don't have it anymore and don't need it anyway, temperatures barely reach -10°C (where I live) which I can manage by simply adding a trouser's pijama under the "normal one"

[Myopic Bookworm]

Just remember to watch your hem!

Oh yes, I had a hem experience! I wore a nice light brown woollen skirt into town last spring: it comes below the knee, and I coupled it with a pair of brown knee-high boots with a decorative buckle near the top. I was nearly home when I discovered that the buckles on the boots had been gradually pulling all the stitches out of the hem! That was a good day for the local sewing shop, where I had to pay to have it mended...

[Faldaguy]

(...) Combine a decent long lined skirt, or skirt with slip built-in; and your own half slip and decent socks, you are as well armored as with any pants. (...)

I don't think so. Roughly 15 years ago, I had a winter pant so warm that I could deal with -20°C without any other layer - save for feets and upper part of my body. I quickly took as an habit to wear a second pant under so that I could remove the brutally hot winter pant when entering in a building. I don't have it anymore and don't need it anyway, temperatures barely reach -10°C (where I live) which I can manage by simply adding a trouser's pijama under the "normal one"

I grant skirts are not reasonable in very cold, or windy settings, but minus 10C is doable. We lived in the Arctic (Yellowknife based & I travelled the entire territory) where -40C (same as -40F) was not uncommon, and often lower, especially with wind factors. At -20F we were starting to feel it was "shirtsleeve" weather, but I'm no longer acclimated to such. There we commonly used layering to handle transitions from indoor to outdoors. A pair of "snow" pants easily slipped over jeans worn with long-johns; t shirt, shirt, jacket, parka (proper ones with wolf-hair hoods, fully seam-sealed and long enough to fall lower than Deni's miniskirts, a scarf, long mitts/gloves and mukluks with liners or similar and thermal socks were all common -- but exterior layering allowed quick (5 minute) transitions. I did not wear skirts very often in those days, but with attention paid to the fabric (weave) liner(s) and a good slip with attention to the hem opening, -10C was readily achieved. The suggestions of petticoats is valid thermally, but not pragmatically. There, even my car had a 40amp circuit for all its auxiliary heaters (radiator, sump, battery, & interior), but -10 could be fine for an evening (if it was dark) out -- maybe my Mother's Belgium heritage! Try a local outing on a wind-free night and let us know how it goes!