For obsessed, self-propelled minimalists like Bmike, myself, or any of the rest of the posters interested in pushing the UL riding into the winter can learn things from the Iditabike culture.

I found a historical gem, an article written by Charlie Kelly in Cycling magazine about the first idatibike with excellent pictures of some of the first bike rigs to head out in the wintertime.

article on first ever iditabike

waterbottle parkas on front fork - check!
rack and panniers ? check!

winter clothes and sleeping systems are bulky, no real way to escape this.