Heavy cotton doesn’t work as they’re a fucking nightmare once they’re wet. Soft shell with some level of water resistance is the way, but I’m not aware of anything suitable.
I wonder if you could get some xl army goretex then get a tailor to take them in while leaving the knees baggy and adding some articulation. Wear those with running legins underneath.
Heavy cotton doesn’t work as they’re a fucking nightmare once they’re wet. Soft shell with some level of water resistance is the way, but I’m not aware of anything suitable.