Winter riding: Warmth to Sweat ratio?
I'm old school. Below 50 degrees I go to my recycling bin and pull out some newspaper. Crumple up a sheet if newsprint and put under my topmost layer. Really wrap it around your torso on cold days. Great for cheating the wind. An old wool sock wrapped around your neck works well for extra warmth.
For your legs there's nothing like a pair of wool tights.