My pleasure!
It depended on the property and schedule - some we drove (we were always driven by our supplier), a couple we did a heli transfer, and some we did regular commercial flights on Air NZ. Flying domestically in NZ is amazing - depending on the size of the plane, there isn't even a security checkpoint. So humane, easy, and enjoyable.
I would not hesitate to recommend self driving at times in NZ - the roads were fantastic. Sometimes it makes much more sense to fly though. For instance, to drive from Christchurch to Auckland is about 8 hours. To fly is less than $100 NZD when booking in advance. Unless you really, really want to drive, it is better to fly.
Thanks again.