But again, it depends on the situation. However, with all things being equal, I'd continue on 3!!!
As Phil Squares says, it depends on the situation. If you have a dozen suitable alternates enroute, and the system redundancy of the airplane is 747-like, and your home base staff deems it a good plan, then sally forth.
That said, I hope you'd never second-guess he captain's judgement - go or return..