I just wear an old M-65 with the liner, something warm for the hands, and a beanie (watch cap). If it gets cold out I'll dig out my old army cold weather parka with the coyote fur ruff, but we aren't there yet. I wish I hadn't lost my old Army Air Force Flight pants, like the waist gunners wore, but those are long gong, lost in a move. I do have some insulated FR bibs, from a frac crew hand via the pawnshop for $100, but they're heavy and cumbersome and I keep them in the vehicle as survival gear, mostly but will wear them if the weather requires and/or I'm out on site. Otherwise, it's a pair of thinsulate bibs I got from Sportsman's Guide years ago, and they do just fine.
Bibs... I usually just wear insulated carhartts, and in intermediate cold, a big ol saggy set of woolies over em... but killer cold is an oversized set of carhartts... well walls, them are really, that I have carefully turned into tin pants, not to soak the insulation, with woolies inside, and regular pants and long johns and etc...
I have had those tins about half my life. they are pretty well shot now, but I can't get any that big anymore... Thinking pretty hard about hiring a seamstress. Them tins are hard to beat. They don't breath, but they don't get wet at all. And with cotton for wicking and all that wool inside em... well, it don't matter if they do.
I learned my lesson with parkas. This last one was always too short... Comes about half way down my butt... Plenty of room for layering, But between the short length and the imitation fur in the ruff... well... not right.
I will probably order one down from Alaska. My buddy up there has an Inuit wife that has always made my mukluks. I will probably have her make me a parka too... The real thing - custom fit - though that is going to cost a pretty penny.
And I know it is too much for working in yet... But as gimped up as I am, moving much is hard to do... so I get cold a whole lot quicker.