Originally Posted by smokepole
If you have the right puffy jacket and a stuff sack, it'll equal about one backstrap in volume. It's a personal choice of course, just like a windproof waterproof shell is.

Oh sure, very true. I think that is more true of the down than of the synthetic.
Personally, the down hunting jackets I have of that type run $400-$500 and I am resistant to compressing them into a tiny sack because they don't ever quite return to their former selves.
On most hunts I am actually hoping for bad weather and for a legit reason to bring some extra layering along - usually doesn't happen.
I think situational awareness is extremely important to calculating your own reasonable altitude and mileage. If you are lucky enough for some colder weather and have the gear for it you may find less need to extend your range and the hunt may, to some extent, come to you. The lightest, cheapest, most frequently used feature I've had on any apparel is a hoodie on a pile or mid-layer.
In the photo below the options for moving became very limited (couldn't go high and dangerous to go too far) but that did not eliminate the hunting opportunities. A little later that day the weather lifted to some extent and the fella on the left killed a cow.
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If I'm planning on spraining an ankle then I'm bringing a SAM splint, extra surgical tape, portable shelter, water pump, food, and so on. For a calamity other than an ankle someone might need even more stuff, but a certain level of confidence in ones ability goes a long way. I actually have had the experience of breaking a bone in my ankle while climbing alone and I found the most valuable apparel in that situation was a high boot.