VA has a current fleet of 136 Aircraft. (Not including non-operational aircraft or Tigerair)
Here's a comparison of AN's fleet to QF at the time & VA's fleet to QF today:
AN:QF = 66:100
VA:QF = 67:100
There's a very good chance VA could very quickly borrow aircraft from their partner airlines - And, I imagine a joint push from VA/SQ/EY/NZ would hold a fair bit of weight with aircraft companies, not to mention the huge orders EY already has and any potentially unused aircraft belonging to it's investments. Also, NZ is retiring 767s as their 787s arrive & SQ is retiring some 777s etc.
The reality is, they could get short term aircraft to fill the gap if they needed them.
Best case scenario, this never has to happen!