Originally Posted by
Muzer
Cheers everyone, that's put my mind at ease! We can definitely afford the taxi cost if need be; it beats the alternative of new train tickets to the Austrian border plus a hotel in Salzburg! (Though I daresay if things have gone that wrong it'll probably be claimable on my travel insurance). Hoping the filght is punctual and without incident but I've had a few flights recently that have been delayed just enough to worry me about onward connections so I'm not expecting much

Flights from LCY are more often than not put on a remote stand and you are bused in. If the S-Bahn is closed then it will be replaced by "SEV" which is a special bus service to (generally) wherever the line is closed to. Personally speaking, it is a pain in the ar*e and the bus is a bit slow as it stops at the usual s-bahn stops. If you are going to get a taxi then book and pre-pay or book an Uber although there are fewer Uber's around Munich than you might expect. If you are going to Salzburg then no need to go into Munich Hbf if your train stops at Munich Ost as the S8 line (from the Airport) stops at Ost.
If you need times, planner etc then look at the MVV website