Personally, I don't see gender impacting this discussion. You can layer as much or as little as you want under a shell. Including down sweaters or parkas on top of other the layers.
As for temps - it is honestly hard to make absolute statements as air temp sincere wind, sun, humidity (such as it might be) - and even activity level - all impact what is really going on. But in my experience skiing, much below ten degrees usually starts to get uncomfortable if there is any wind at all. As soon as true air temps are below zero F, wind or airflow on exposed skin starts to be somewhere between uncomfortable and the need to be careful zone. Somewhere between 5 and 10 below, it seems it becomes a real danger. The one time I spent a day out at -12 F true air temp, we made sure there was zero skin exposed - full face masks, etc, etc. And rechecked each other routinely. Even taking a glove off down to a liner glove was painful after a moment or two.
Again, all of those factors I mentioned influence what is really going on. And different strokes for different folks. But I know when things start to get really cold, the crowds drop off pretty quickly (sometimes including me...). I've seen this enough places that while I have not skied the eastern US or Canada, I'm reasonably sure it plays out similarly there. Hence my assertion that optimizing for super cold conditions does not really matter for most people. And that furthermore, true subzero conditions demand layering even within any typical consumer oriented insulated garment.
Another thing I have noticed is that manufacturers often use insulation layers to mask cheaper fabrication of the shell proper. Obviously there are some fine insulated tech oriented garments out there. But my sense is that this is less than typical. A 3 ply shell leaves little room to hide anything in terms of stitching, taping, welding, etc. What you see is what you get...
Finally, regarding the "baggy" comment above...any shell leaving room for layering options is likely to be a bit "baggy". No need to go crazy baggy, but there is a point where going for sleek is trading off function for fashion.