I diverted into Amsterdam just after midnight once. That's a major airport in a major European city and open 24 hours a day..... -ish.
... There was zero support available at that time of day - after curfew and the last commercial flight, non-essential staff go home. No ground power (even though my APU was U/S and I was running a live engine for power). No stairs. No passenger transport from the remote stand. It took hours to simply get the passengers off the aircraft - and that only happened as a tower ATC guy (who was going off-duty) used to work ramp and still had a valid airside bus licence.
Flying at night, you can be more "remote" than you think - even over high density areas.