If you are sitting still getting ready to glass and it's in the teens/20s, you will probably be extremely cold with the clothes list you posted.
I feel like I finally got my setup dialed in the last year or two for being out on days where you may start in single digits and get up into the 40s. I live in CO and spend a decent amount of time outside.
Base layer: saxx underwear, add lightweight synthetic long underwear if highs don't hit 30. Sitka core lightweight, FL aerowool, or Acclima woolnet (mesh merino wool, this is awesome when it's cold)
Mid layer: I often wear a Rab fleece made out of polartec alpha (same stuff in new sitka ambient) with no face fabric. Very light, very breathable, doesn't stay wet long. I also have a Sitka core heavyweight hoody that is about as warm, but heavier and less breathable. The Sitka gets the nod if I will not be wearing a softshell jacket
Outer layer: Stone Glacier De Havilland pant and jacket. Massive leg and underarm zipper vents to dump heat when moving. This is key if you're going to wear a less breathable softshell outer layer, IMO. I can hike on level ground at a slower pace and be comfortable in the teens, and go uphill or go fast in the 30s and into the 40s and open all the vents to avoid getting super hot.
Insulation: First lite Chamberlin jacket and uncompahgre pants. When you are sitting still glassing in single digits or teens most down jackets just don't cut it. I'd probably buy different pants in hindsight, but these work well enough.
You can get away with uninsulated boots in much colder temps if you create a vapor barrier between you and your insulating socks. Wear a thin liner sock, put a breadbag over it, put on heavy wool or alpaca socks, and it will keep the moisture from your feet from getting to the outer sock and you will be much warmer. I just spent 11 hours straight standing on 4-8" of snow in uninsulated boots with this setup and felt good, despite normally having very cold feet.
Cheap flip mitts off Amazon for less than $20 have been the best gloves I've found. if it's VERY cold you can take the chemical warmers that are meant to stick on your toes and stick them inside the flip part that goes over your fingers.
I will back up the gaiter recommendation for snow.
If you're going to be hiking, you need to start off uncomfortably cold or you will soon be sweating and stopping to pull layers.
Hopefully this is helpful advice from a Texan who spent years testing things before finally being comfortable in rifle seasons here in CO.