Cooler weather bottoms systems

I'm in southern/central CA so I realize my winters are probably different than most. I also tend to run hot and need very little insulation compared to others. Anyway I tend to usually hike in my same pants (Patagonia Rock Guides) or shorts (Patagonia Nine Trails) year round and just put my wind pants over the top at stops or if I start to get cold.

If I'm hiking in light snow or temps in the 30s or below, I'll carry and sometimes end up wearing a thin pair of merino or capilene tights under my pants or shorts.

If I'm actually hiking/camping in real snow, I'll wear the long underwear bottoms under a more dedicated soft shell pant.

If I'm expecting temps in the lower 20s or colder at night, I'll sometimes bring along a pair of down pants to use around camp and to supplement my quilt.

It seems like, based on my own personal experiences anyway, that I don't need much insulation on my legs while walking.

here

I like quilted fiberfill pant liners or underwear. Example at link above.

There is a company that makes some green quilted long underwear that has heavier nylon and less fiberfill. I prefer the military surplus ones due to the warmth per weight advantage.

For midwest winters, I like something a little warmer than the rock guides or columbia titanium pants I wear during the remainder of the year. I use a light stretch woven outer(patagonia guides) with cap 1 long john pants underneath.

Rain pants, soft shell pants, silkweight long johns and Power Stretch long johns. Combine to suit.