Nice and easy this morning for this - managed to get the last seat in the house on the day I booked my EntryPass ticket for for the mother (because it was heavily implied that if I didn't take her to see the Olivias I would be disinherited).
Lucky you Squire S - my iPad cached so I kept getting the error message. By the time I got in, there were very few seats left and nothing I wanted. Ah well - there's always Friday Rush. And I did manage to nab a £15 seat for Oslo so it wasn't a total loss...
I'm still looking for tickets! Friday Rush difficult alas because of the travelling.
It's definitely worth checking the site regularly, because in the past few weeks quite a few tickets have popped up. I would guess that I've seen about a dozen seats in total while I've been checking. They have been a mix of single seats as well as small groups, and the dates are obviously scattered, but if you're flexible or going alone then you might get lucky. Presumably returns will pop up more regularly as we get closer to the dates.
One thing to bear in mind is that on the dates page www.nationaltheatre.org.uk/shows/mosquitoes-whats-on-listing they don't update/remove the text at the top that says "Mosquitoes is now sold out" when returns pop up. I've generally found the easiest thing to do is to search for the phrase 'book now' which will come up with nothing if there aren't any tickets, or will take you straight to the specific day(s) if there are.
Good luck. Hope you manage to get tickets somehow.
Also bear in mind its not unusual at all for a whole bunch of tickets to appear closer to opening night once they've sorted out staging. For instance "The Flick" was sold out in the Dorfmann for ages then suddenly lots of seats showed up. I'm sure someone will point out here when / if that happens!
Yes, I've just rung them up, and they said it could be anytime, but more pop up closer to the start of the run. They couldn't give me any info on any possible NT Live broadcast either - do they do them from the Dorfman?