I use lots of different materials and styles for my out door pants.
Frankly, for dry weather, even when it gets pretty cold, as in below freezing, the Desert Camo BDU's work quite well. I like my hiking pants loose fitting and durable. I've also used lots of nylon pants. The last ones I got I bought from Cabela's. Zip off leg options are nice to have when it's really warm. I'm probably as fearful of hypothermia as anyone, but I'm not worried about using a cotton blend in a dry climate. I really like the big side pockets as opposed to using front pockets.
I, too, have literally lived in my Nylon and BDU pants for days. Very flexible in a wide range of temperatures.
I've got two pair a Cabela's Whipcords. Bought them in my usual waist size and found them too restricting. Bought another pair two inches larger and they are nice and loose fitting. So one gets used for casual wear and the other for the trail.
For cold weather, below freezing for much of the day, I favor heavy, 24-28 oz. wool. With the minimum of base layers. Capeliene of course. That way, when the day gets warmer or I'm on the sunny side of a ridge, they aren't too warm.
I buy them long as well. When I raise my leg, the boot top stays covered. Or I get extra material under my gaitors for additional warmth.
All I can really suggest is buy what you think is good and try them out. Sometimes what you think won't work well does and vice versa. The first, tighter pair of whipcords I bought were like that. Thought I 'd like'em and found them too tight. My first expereince with BDU were just the opposite. Found they worked much better than I thought they would. E
