I’ve. been taking groups of people into the hills for over 12 years now. I discovered bothy bags / shelters on my first Winter Mountaineering course and was hooked ever since.
I use the Terra Nova range which comes in 2,4,8, and 12 man.
Personally I use a 4 man for up to 2 people with bags, and my 8 man for up to 5 people with their bags. Great for getting warm and out of the wind. I use mine almost every time out (if I’m not putting up a beach shelter). They are a superb piece of kit… even if it’s just to take a break and eat some food / take some fluids or have a rest.
P.M. if you need a video of us using one on a wild weather activation.