I've travelled quite a bit (as you do when you go to and from New Zealand), and even films that have been back and forth have never suffered any ill-effects.
Travelling round Europe, the film always goes through the handcarry scanners, and never had a problem either. I used to carry a small 35mm on business trips (Minox 35GT), and sometimes the film in that camera had 10-15 trips through the handcarry scanners, and still no problems.
XRay scanning of handcarry baggage has been used in airports for years in Europe, and very few people have experienced problems.
If in spite of the overwhelming practical evidence, if you are still worried, forget about saving a few dollars/euros and purchase the film and develop it locally.