I believe the MOCA is around FL115 on that route, nothing a 777 can't handle on one engine.
ETOPS is all about planning, as long as that part is covered the actual flight can go over those limits or you might choose another alternate if it's better/nearer by.
Although willingly flying over 3 hours on one engine remains doubtfull, the checklist tells us to land at the "nearest suitable airport" and I sure as hell will! :-)