Cosc,
I think I need WAY more layers than KnottedYet seems to need in the cold. I get cold easily, and I don't get too hot and sweaty like most people seem too.

So I lifted this description from another post I recently wrote, perhaps it will help you a bit. You probably don't need as many layers as I typically do to keep warm, but then again I am riding for two hours and that can get fairly cold:

This morning was 35 degreesF, no sun, breezy. In other words, pretty cold.

I layered up pretty well.
Top: bra, merino smartwool longsleeve crew, thick wool sweater, SheBeest WindPro jacket. Bottom: SheBeest chamois TechTights, SB WindPro non-chamois tights.
Thin merino socks, thick wool skiing knee socks, hiking boots. Smartwool glove liners, Ibex ski gloves. LouisGarneau Junior balaclava, SmartWool helmet liner.
Seemed like a huge amount of clothes to put on, but by the end of my ride I was glad for every item.
My ride was 21 miles, about 2 hours. On some downhills I had tears streaming down my face because of the cold wind. My glasses frames were cold on my nose bridge. Never got overheated on the uphills, but stayed refreshingly chilled (in a good way) throughout my ride. My toes got cold in the end. My fingers got cold for a while, then warmed up again. Next time, 2 pairs thick socks instead of one thick and one thin. I just LOVE my "junior size" balaclava- kept my neck and ears snuggly and kept my chin nice and warm in the wind. It fits my small head nicely- no bagginess.