its standard procedure to close the airport at a licensed airfield until such time that...
Ah right, so that's closed for some tens of minutes whilst the situation is secured, then, not for hours until the dead aircraft is removed. Fair enough. So returning students etc have the option of just flying round in circles for a while.
If you don't make contingencies for the unexpected then you shouldn't be flying.
Eh?? Where d'you get that from?? Try re-reading - you will see that I precisely
do make contingencies for the unexpected - the briefing I mentioned includes explaining to the rear seat passenger how to open my bag and extract the Pooley's in case Cambridge is closed and we need to land elsewhere.
There are lots of nasty things that I don't expect to happen, but I plan for them all the same, as trained, as any pilot does.