As others have said, if you lose all your autopilots and were planned in RVSM airpace then you have a decision to make. Do you have enough fuel to continue to destination, or at least get closer to your destination while flying at a non-RVSM altitude ? Are you and your crew competent pilots who can hand fly an airplane ? What a scary question, huh?
My god, the first airline I worked for we didn't even have autopilots installed !! Six to eight legs per day with multiple approaches to minimums. Later at a major in the Unites States, nobody, but nobody, used the autopilot below FL180. This was on the east coast of the United States as well. Nowadays I fly with guys who push the autopilot button at 200' after takeoff and don't disconnect until less than 1000' on landing. Yes, in certain circumstances that is the smart thing to do, but we need to maintain some hand flying skills for the times that they are needed.
In your example, 11 hours is a long time to hand fly. It really would mean that two pilots need to be alert at all times, especially at night over water. If you have an augmented crew and they are willing you could set a pattern of rest breaks ( thats rest from hand flying ) and continue.
My two cents,
TP
TP