For bow hunting:
I’d go with a light weight synthetic outer layer for days it’s cool but not cold. I like the Kuiu windpro for that application. Or, a gen Iii military fleece. I’d go with the Kuiu proximity for those 20 degree days. That’s all you need for your outer layer on top.
My pants are always going to be wool. In those temps a light pair of military issue wool trousers work awesome. Pair it with any baselayer material and you’ll stay warm. Pair it with merino bottoms and you’ll stay cool when that 20 degree morning turns into high 50’s too. I much prefer merino for my bottom insulation.
My only advice for top base layers is it’s best to wear both materials on top. Polyester wicking is ‘da bomb. If you sweet it up, sliding that heavier polyester layer and a merino on top, with a vest or jacket that breathes over it, will literally bake that sweet right off you in no time. You’ll be toasty warm instead of clamy cold.
The base layers above and my chosen outer layer is what I’ve found works best for what you described. I hunt the same type areas and it’s taken me a couple years to get this down.
Puffys are great but, they do not breathe at all. (Minus the Kuiu kenai. But, it’s not whitetail stand warm either. Save the money for better baselayers.) Anyways, I no longer carry puffys unless I intend to set all day in the same spot and I’m rifle hunting. Taking them off and on as you move and set sucks if you move much at all. Or as you hunt. It’s just not my thing for bow hunting. But, a nice fleece vest will put the cool system into the upper fringes of your cold gear. While being much more packable.
For rifle season here, I pack in and wear everything I’ve listed for cooler weather but, throw in a synthetic woobie I made. It’s light and super warm.
Temps here during rifle season might be 40. Or, it might get down to zero and stay in the single digits or teens where I hunt. And, that Woobie makes it all possible while not being bulked up.
I really like this whole system. But, as a whitetail bow hunter you need quiet and breathable. So, I’d shy away from merino top layers against your skin as they simply don’t dry well. Polyester does. It’s the best skin layer to choose anytime you have to have some protection while moving and when you know you are going to sweat. Then add insulation over it once on stand and it will bake the moisture right off you.
I hope this helped.
