The weight hierarchy
Lightening a shelter saves more real fatigue than lightening a stove or a headlamp, because a shelter is both weight and bulk. A pack that fits properly beats a pack that is lighter but rides badly — shoulder and hip pain ends trips far earlier than two extra pounds do.
Where not to save
Sleep insulation and rain protection. Cutting a few ounces on a quilt rating you cannot trust or a shell that wets out is how trips become miserable. Spend there — and spend on the pad before the bag, because the compressed underside of a bag insulates nothing.
Picks
Two-person trekking shelter
Highest fatigue-per-ounce saving available. Also the hardest thing to buy well from a spec sheet alone.
Awaiting ASINInsulated sleeping pad
R-value is the number that decides whether you sleep or shiver. Cheaper than the quilt and just as consequential.
Awaiting ASINClosed-cell foam pad
No valve, no chamber, nothing to puncture, and the cheapest insulation sold. R-values in series add, so a foam sheet under an air pad raises the total roughly by its own rating, and it puts a puncture layer between the chamber and the ground. Buy the second layer before you buy a second pad.
Awaiting ASIN