>>2591159you could sleep in an expedition-grade down one piece suit in pretty gnarly weather.
i don't really get the point of doing so though.
any weather you'd need with you'd definitely also need a sleeping bag for.
and if you're trying to replace a sleeping bag, its just going functionally be a heavier and less thermally efficient, shittier sleeping bag at 4x the price.
there's no weather range where it would replace a sleeping bag, and also be something you could hike in. it will always be too warm to wear in any weather you can replace a sleeping bag.