In total from polypro baselayer and shirts, ending with fleece sweatshirt under a windbreaker shell, I had nine layers on the top. That sounds like a lot, but with the exception of the fleece, the layers are all very thin, so I didn’t look too bulky.
The bottom was AmFIB tights, polypro baselayer on top of that, then loose workout shorts and then loose workout pants.
For feet I had wool socks, handwarmers on top of the toes, then cotton socks, plastic bag corners, then sneakers. The chemical handwarmers on the feet quickly quit working, as they need air to sustain the chemical reaction.
Hands were kept warm polypro glove liners with handwarmers on the back of the hand, then Louis Garneau lobster claw gloves. My hands and fingers never felt cold.
On my head I had a fleece balaclava over head and mouth (nose exposed), then polypro balaclava over top of head and ears. I taped up the vents on my helmet. I probably could have used an extra layer on the top of the head.
Except for the cold feet, it was an exciting and refreshing ride. I don't think it would have been safe to ride any further with my feet getting cold. I'll need to develop some other foot warming strategy.
Here's an observation about how well the technical fabrics work (even the cheap ones). Of the nine layers, the seven closest to my skin were the technical "stay dry" fabrics. Next came the fleece, then the Vagabond shell. When undressing for my shower, the fleece was visibly damp. It's amazing to think how well those seven layers wicked away my moisture to that fleece. Wearing cottons and fleeces alone would have made for a miserable ride.
I write this, not to solicit comments or show how hardy I am, but to document what clothing works, and maybe what doesn't work. If someone else finds this information useful, then it's all worthwhile.