Difficult to be specific. It is not so black & white. It's a command decision and could depend on many factors such as weather, familiarity etc. The major consideration is a safe landing. By the time you have secured the a/c and run various checklists it will take about the time you fly 50-70nm. Rather than spend that time positioning to a dodgy airfield you can spend the same time running Cx lists en-route to a better option.