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!
Two ways of no padding for your saddle: material that gives (Brooks leather, rubber, etc) or you have a rock for a butt.