the missus rides and really feels the cold and it can get fairly chilly here in the deep south. She always wears a long sleeved thermal top underneath, she's got a cheap one and a dearer one and she says they both have similar warmth. The dearer one is trendier so she can wear it with nothing over the top if it warms up. The cheaper one looks like grannys undergarments if you know what I mean. She always layers, usually a woollen jumper over the thermal, or two if they're thin. Over that she wears an unlined leather jacket for heavier protection (starting to sound like a tampon ad?). She never rides without a scarf or neckmate. On the bottom half she wears kevlar lined denim and on the coldest days thermal longjohns underneath with wooly work socks. She still gets cold but is happy to ride most times of the year.
Hope this helps.
Great. Might check it out too.