I assume you are looking for trousers to coordinate with a sports jacket or blazer. You will be able to find flannel in a 15/16 ounce weight in Cambridge, oxford and clergy gray. Grey is a neutral and will go with anything. Cavalry twill also is made in a 16 ounce weight. The "officers pink" shade is a natural with a navy/blue blazer.
For more casual wear you can look for tweed trousers. Some individuals do not like the "fuzzy" feeling of tweed against their legs. Get them lined in cotton.
Winston Tailors/ www.chippneckwear.com
Maybe in Baltimore, which to me hardly has a real winter. But in Chicago, waiting for the train at 8 AM when the temperature has not yet
risen to the predicted high of 10 degrees F, corduroy without long-johns is a non starter.
Well, this winter was quite worm, wasn't it?
Honestly, it's not cold that is so bad, but when it's windy nothing helps except (as CM mentioned) overcoat that stretches well below knees.
BTW, I'm a smoker, in Toronto, I know what I'm talking about.
If you have not worn heavy trousers before, try out a pair first and lining does make a difference too. I don't think I could wear a fully lined flannel trousers even in very cold weather, although I an wear 14oz half-lined flannel in late-summmer.