A simple way to do this is flannel-lined jeans. The version of these made by L.L. Bean have worked well for me. They trade off a bit of extra bulkiness for substantially greater warmth and mildly improved wind protection. Random forum searches suggest that the fleece-lined ones are even warmer, but you lose the cool plaid patterning on the rolled up cuffs.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.