Part of my line training was flying a normal line flight which at some point the captain 'dies.' This was an A320. I was type rated with some experience on type and it still was bloody hard work flying single crew (one of the requirements to be signed off before my first route check). Also worth noting that it is a bit different flying with 160pax single crew for real than in the sim. BTW The captain was still monitoring obviously however if he had to say anything you would fail.
I certainly wouldn't fancy flying a jet type I am not rated on single crew - I could probably get away with it on another Airbus but Boeing would be tricky for me I think (only prob 25 hours level D on 73/75 sims). Let us hope this never happens for real.
Certainly a talked-through autoland would be the way to go.
Tom.