Why does everyone think New Zealand is safe? It's a commonwealth country and has huge defence connections to the US and UK.
For the crowd simply hoping for some variation of On the Beach, you should be aware that a nuclear war in the 2020s would almost certainly see Australia targeted by Chinese nukes.
In an apocalypse scenario, they are just extra mouths to feed - I wouldn't waste any missiles to target rich people's mansions in any country, but the locals might have plans for them...