But it must be a slightly hairy prospect to routinely wander off to find
Bears far out over a rough cold sea with that one engine.
While I take your point about the perceived wisdom of utilising the F(A)-35 as an air defence fighter, I think the single-engine issue is a red herring.
F-16 operators, such as Norway and Netherlands have been operating over the rough North Sea for decades, as have the Swedes with the Gripen in more recent times, and as the French used to do with the Mirage-series aircraft. Also, the USAF routinly flies its F-16s over Alaska, so the single-engine v twin-engine debate isn't the issue some make it out to be.
Getting back to F-35 air defence capabilities though, it is interesting that the majority of those signed up for it will not be operating mixed-fighter fleets, but will be fielding the Lightning II as their primary fighter. Will be v interesting to see how this develops...