I live in the bay area so it's probably not getting as cold out here as it does where you are. However, I can tell you what works for me when it gets down to 40 oF or so. I typically wear a pair of cycling tights without the chamois underneath a pair of cycling shorts. To that I add a jersey, arm warmers, headcover (ie doorag) underneath my helmet and long finger gloves underneath my cycling gloves. That works down to about 50-55 oF. When it gets colder than that, I'll put on a thermal vest or a cycling jacket with long sleeves. I've found that as long as I keep moving, this kind of setup works pretty well.

You may want to consider neoprene booties to keep your toes warm. My brother who lives in NYC says he has to have these for winter riding