This sounds like Carhartt thermal coverall territory.I own an auto repair shop and and I'm constantly in and out of doors, getting in cold vehicles down to -20 degrees, and looking at things in the parking lot. Mid-weight thermals keep me from freezing to death outside and don't overheat me inside. I literally wear them all day every day from November to March.
Alan
On a semi-related note, I've been looking at reviews of wool mesh baselayers. Not so much for winter, but for shoulder season. Like so:
Unisex Wool Thermo A-Shirt Singlet Base Layer – Brynje USA
www.brynjeusa.com
I think they'd work in winter too, so long as they're paired with a windproof outer layer.