My set up yesterday consisted of

Walking in:
Merino base layers, reg weight
Regular hunting pants
Puffy down vest


At the tree I put on down pants, down jacket, neck gaiter, and my cabelas stand hunter bibbs I haven't used in a couple of years. And a orange beanie cap.

Boots were insulated and sized larger than I need and wide, put a foot warmer in there.

I was toasty and could have been out there in the teens and been extremely comfortable. It's usually my feet that get me first, and they were extremely comfortable. The down layers have been key for me, they weigh practically nothing, I think all together the vest, jacket, and pants weigh about 2 lbs, and they are the warmest things you've ever put on your body.