Speaking of layering...
For me
Headband/earcover is first level
Then gloves, long sleeve shirt, jeans (any order or combination until all three)
This gets me into the 40's if I'm moving or not out long; sometimes the mid 30's. But it depends on the humidity, windiness, whether the sun is out, and my mood.
Then add a sweatshirt or heavier flannel shirt
Then a coat
That is usually good down to mid twenties unless I'm out a long time and not moving very much.
About here, I switch to more insulated boots (all insulated instead of just the bottoms).
Then hat instead of earcover, mittens instead of gloves, a scarf (any order)
That gets me down into the teens.
Then a thermal vest undershirt and/or another layer of flannel shirt and/or add wool socks and/or add flannel lined jeans.
Pushing zero or below, I start switching to alpaca.
The colder it gets below that, the more layers get switched to alpaca. Eventually, I just add more alpaca. Or cashmere, or cashmere/angora before I accumulated enough alpaca.
All this, assuming it is dry enough and not horrendously windy. For windy, nothing beats leather. Certain Carhart jackets come close, though, if they are in good shape.... older ones, at least. Last time I looked for a replacement, they seemed to have changed a lot. I ended up mending mine.