Filson. Not cheap, but not overpriced. So far, their guarantee is good for 120 years (when the business started). Seriously. If a garment needs repair you have two choices. They'll replace or repair. Seattle is Filson's HQ. A friend saw someone bring an old coat in for repair and the
Filson guy exclaimed that it was one of the first ever made. He offered to give the guy any coat in the store plus $500. The guy said no. Repair it. I was my great grandfather's.
For wet conditions, you'd want the 'tin cloth' fabric.
https://www.filson.com/oil-finish-single-tin-pants.html#sku=11014005-fco-000000062