I ride a fair amount (40,000 or so km a year) and do a fair amount of commuting. I ride until there is snow and ice on the road and don't really worry about temperature. For the most part I take an approach opposite of what most people here do.
My cold-weather gear consists of an electric jacket (warm and safe), a soft-shell jacket for more warmth, fleace pants from Aerostich and a pair of heated gloves from Gerbing. I wear the same riding suit summer and winter (Aerostich Roadcrafter two-piece) and the same boots and socks. (Alpinstar Web-Goretex boots and Tilley travel dress socks. Only in all day rides well below 0c would I bother with heavier socks and even then rarely.)
I generally start with what I would be comfortable wearing in a restaurant at a lunch stop. This means no long underwear, maybe a moisture wicking t-shirt (and that is becoming more rare for me) and just whatever pants and shirt I might wear at lunch. If commuting when cold enough to wear electric I leave my work suit-jacket in my topcase. Basically I layer up from my street clothes as the need arises with various combinations of the heated jacket and the soft shell. I generally have three different categories of gloves in my tank bag. These range from light mesh, intermediate and heated gloves. In summer I havea small windshield, in fall I put on a larger shield. I have the Suzuki Handguards on my V-Strom and I close of the bottom of them when it gets really cold.
..Tom