This is a place where you can really save a lot weight, but you have to think a lot about how you do it, as it can also put you in some really dangerous situations if you go too light and your sleep systems fails or you just don’t know how to use it properly.
I really like my floorless shelter for the longer trips. There is lots of room in it, which is really nice when you have to live in it for a long time. When it’s cold, I can put a stove in it, and I’m nice and toasty when the wind, rain, and snow is howling outside.
On the other hand, if the trip is just for a few days, I will often just bring a bivi bag. It doesn’t offer a lot of room, but it’s light. Lastly, if I’m over tree line in the mountains, I will often go for a 4-season tent, for safety reasons.