How many international scheduled flights has Invercargill attracted since extending it's runway? Answer a big fat zero. Other than the odd RNZAF Orion going to the southern ocean on patrols the cost of the extension has produced limited rewards.
Dunedins 1950mtr runway seems to work well with the bus on the trans Tasman routes with the very odd flight goining via CHC for gas on rare high temp low pressure days maybe once or twice a year.It occured more when Freedom used the 733.
Trans Tasman flights from Dunedin would only ever need the A320 or the 738 in the immediate future so a runway the size of INV is hardly warranted.
With ANZ taking over SJ routes hopefully MEL all year round instead of summer only and the reintroduction of OOL might happen. Heres hoping