I rode 37 miles today. It was around 25º when I left, and the wind chill was in the teens. There was a steady north wind blowing hard the whole ride. The only thing that got a little bit cold was my left foot. If I had one more light layer on my feet, like a pair of peds, I'd have been perfectly dressed.

upper body:
Sports bra
Cashmere turtleneck sweater
EMS techwick base layer (the kind with holes in the sleeves for your thumbs)
Craft Jacket
PI Barrier jacket

lower body:
Terry knickers
knee high bamboo socks
polar fleece socks
ballet-style leg warmers
mtb shoes

head:
lightweight buff (worn balaclava style, sometimes up over my mouth)
cycling cap
helmet

hands:
1 pair of non cycling winter gloves

My friend Sarah had on a balaclava and tights over shorts, but other than that, we had on about the same amount of clothes. She wasn't cold, either. I thought this would be helpful for anyone thinking about taking a cold ride, but not knowing what to wear.