If only one pilot is left in the flight deck wouldn't we need like a camera link to the flight crew rest and system and nav/weather displays in the back to give the second guy the immediate big picture? What happens with a broken windscreen, cockpit fires and such?
Even AF447 with a full crew left not enough time for the captain to regain situational awareness/control after he had to be called back from the crewrest.
I think it is generally wrong to use a cockpit layout made for two with only one person at work.