I have wondered how things like this work out...
If it cold enough that I need to wear my sleeping insulation while I am bobbing about in camp and cold enough that I can wear it without overheating and without wanting to take it off... wouldn't I be cold when I go to sleep. ?
If the insulation is adequate while tottering about camp (I don't overheat), wouldn't it be inadequate when I stop moving and my body rests and metabolism drops...? If this is the case, I would need extra clothes to keep me warm during the night. If I have extra clothes to keep me warm, wouldn't I wear them around camp?
I guess the wearing sleep insulation around camp plan works if it is really a bit too warm but it is vented to make it okay/tolerable. Then it is still warm enough overnight when it is buttoned up ?
If I was comfortable walking around wearing all that like the fellow in the picture, I would expect to be chilly when I stopped moving and went to sleep (maybe not right away, but some time during the night). Even if I tucked in my arms and lower legs...