156
Surprise Blizzard
(lemmy.world)
My commute was 25 miles each way, 1400 feet (426m) of ascent each way, with no transit option. Last winter, a surprise blizzard rolled in during the week. My ride home took me 2.5 hours, rather than my usual 1:40, but I managed to stay upright the whole ride despite riding on slicks. Fixies and foul weather, better together!
More or less....
Ideally you should be resisting with your legs on downhills to control your speed before it gets to that point though