Generally, I use two/three pair when hiking/paddling.
One is always kept dry, usually in my sleeping bag for sleeping in a large thick pair.
Paddling trips often require two. These are both size medium. But are equally thick hikkers. One usually gets soaked in water. I rinse these out at night, then set them out to dry, when I take them off at night. The second set is mostly dry by the second morning when I put them on. Straight hiking is about the same, but my feet sweat enough that they get damp, even without streams to cross, or mud holes to hike through. They, again, get mostly dry by morning.
Both are wool/merino wool blends with fair elasticicity.
Winters?? I don't hike in winter, but when I was doing that, I used heavier larger sized socks in a larger sized boot. This worked as well as any for hiking.