We have used merino wool (they might be blends, not sure) from Darn Tough, Smartwool and some Costco off brand (I want to say wigwam, but that might be wrong) for our summer and fall trips. I have stayed comfortable thru about 35 degrees F, though my boots have some amount of insulation. Most trips I only have one extra pair of socks along or maybe two at the most. I keep my "camp socks" dry at all costs, even if it means having to pull on socks that are still wet from the day before, but merino dries out pretty fast and keeps the stink to a minimum even for 7+ day trips.