How long of an endurance drive could a F1 car do?

How long of an endurance race could be driven with a Formula 1 car before the engine or some other part of the car would probably fail?

Formula 1 races last for around two hours. It would be feasible to drive five or six of these. This all obviously depends on how much power would be extracted from the engine. But half of the Lemans 24h race should be feasible, some twelve hours or so.