cleaned the discs I had after a couple years and replaced the pads and then the sound was quieted down ..
BB7, now running with Kool Stop's organic compound pads .
..roller brake turned to molasses in cold weather and the bike didn't roll as well. Perhaps a drum brake?
the Shimano Roller brake is a greased hybrid somewhat coaster brake like in that it runs in grease which will harden in the cold.
the Sturmey Archer Drum brake hub is a dry friction pad , and is unaffected by cold weather .
The bike I break out when the road is Icy is an old MTB with drum brake hubs and studded tires .. that I leave on.