Ditto tsl's comments, which I agree with wholeheartedly. Like mtalinm, I wear bib shorts under my (single pair of) unpadded bib tights. In fact, I pretty much wear the same rotation of bib shorts all year round, supplementing with knee warmers, leg warmers, and then the bib tights, depending on temperature.

The only other thing I would add is that for both hands and feet, I strongly support using liner gloves and liner socks underneath the warmer layers. That's made a world of difference for me in both locations.