The last time I rode in 15-degree weather last year I wore: a Gore windproof jacket, a Nike microfiber vest under that, a longsleeve jersey and a long sleeve wool baselayer on top. On bottom, I wore a pair of shin-length knickers and tights. On my extremeties, I wore PI Gavia gloves, wool glove liners, wool socks, , wool socks, and my regular cycling shoes with charcoal warmers inside, a balaclava, a hat and my helmet.
Thirty-five miles in those temps would probably undo me. I usually follow the adage of "ride the temperature," so if it's 15 degrees, I ride roughly 15 miles, at most. Is it going to warm up much through the course of your ride? If it is, then just make sure you can take a layer off if you start to overheat.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher