Milsurp uniform wool pants. This pic is the East German variety, available for $13. The only drawback is that they have button flies. I HATE those things. I replaced them with zippers.
They're good down to maybe 20F and up to 70. A pair of polypro long johns takes them down to well below 0. The uniform pants are lighter than the heavy cargo pants and easier to wear. Cheap, indestructible, comfortable, quiet, and butt ugly, but who cares.

[Linked Image from cdn11.bigcommerce.com]

“In a time of deceit telling the truth is a revolutionary act.”
― George Orwell

It's not over when you lose. It's over when you quit.