it is funny how big your sleeping bag you think it is to craft, change clothes, and do anything. for my understanding, the sleeping bag is just fit to one (normal) to two (big) persons. also, i dont think it will fit in the game "For the current coding" of the night animals. Predator to be exact. Once I tried to lure a zebra in the pit of lions and bear, but they didn't touch it. instead, then try to reach me, and jump to where I am standing. during the day, they seems passive, unless you come near them. well, even the other animals will be attack if they come close to a predator. but during the night, you are the only prey in their eyes. so you cannot sleep in an open area. unless the coding is change, it is impossible.
you can be attack even you are in your sleeping bag.