I hunt from highs in the 80's sometimes in mid september with mosquitoes that could carry a man away to sub 0 highs in December with wind chills in the sub -20 range.
I don't even wear bibs, they're generally too restrictive. I don't like carrying a side-arm in them, which I always do when bow hunting. I don't like how they bunch up in the stand, they're too heavy(at least the one's I've had).
I have a layering system.
3 base options - hot/medium/cold
lots of mid options - none/tshirt/longsleeve shirt/sweatshirt(sweatpants)/fleece/wool and you can layer these as need be
1 outer layer - This is the jacket that I wear almost the entire time unless it's too warm...so anything above 50ish degrees. Below that I add the jacket....as it gets colder, I start moving up the layers of mid and base.
With my warmest base layer, wool, and fleece mid layers, I'm good down into some real cold temps. I used to wear bibs/heavy jackets, but they're too restrictive and seemed to never be the right temperature...either I was still cold OR too warm. My current layering scheme seems to keep me at the right temp more often than not. I generally dress for a bit colder than I think I need and I can shed a layer if necessary.