I don't ride below freezing except by accident. 5c is just okay.
C3 helmet is warm and fog proof
Thin Oxford balaclava to keep the earphones in place - worn all the time.
Neck protector with bib front and back ...that makes a huge difference.
Long sleeve base layer - poly
Columbia poly fishing shirt for the pockets and another layer
ColdPruf over sized long underwear top over that ( the stuff is amazing ).
If I want better warmth I sandwich the Cold Pruf between the base layer and the fishing shirt.
Heated glove liners - First gear
Scott 3 season jacket ...no liner ...I prefer the ColdPruf.
ColdPruf extreme cold dual layer long johns. Sometimes I use Dr. Skin tights instead.
Pumpgun Knee armor - it has very good coverage both for protection and warmth.
AirGlide 3 over pants without the liner or knee armor
Milwaukee Trooper boots with battery heated inner soles. I find my feet most vulnerable after a time. If I was doing distance I'd switch to first gear heated socks,
First gear glove liners under Eddie Bauer First Ascent gloves....no armor but flexible and really keeps hands warm ...never go above 2 on the heated liners.
This year added handle bar muffs that will come in tomorrow. Those might take my temperature range lower at least for short rides.
The Madstad winscreen and side deflectors keep a very quiet air pocket and the C3 is very warm ( almost too warm in the summer )
Riding the other day, my feet stayed pretty warm so maybe the CB500x has some warmth coming off the engine in that area but it was mid -teens
