I'm not onboard with the idea of saving only when sleeping, for the same reason I approve of not letting companions have permadeath. Companion permadeath and location-specific saving is alright in theory, and works with games with a sort of roguelike quality to it, but Bethesda's engine is not capable of handling these two things properly. This can only result in crashes setting back progress by two or even three hours, while companions may suddenly teleport into the sky and fall down and die. The rest has already been mastered by DayZ, Rust, and several other survival walking simulators. All those other games are still in Early Access and are still buggy, so I guess that fits with Bethesda's theme so far.