On our travels this time, actually it was January, we ventured around in New Zealand's north island. Unfortunately we have to conclude that New Zealand is also not the most Naturist friendly island, but then again we're spoiled with the likes of Germany and France of course.
We managed to stay in only one Naturist site, Katikati, between Tauranga and Auckland. This camping with some bungalows as well is very nice, relaxed with some nice amenities like Jacuzzi, Pool, Minigolf, and others. You see couples, singles, same sex couples, a mixture of all sorts so a decent copy of society.
There are a few other places seemingly (but it's not very well advertised as when you find the websites of the venues there is most of the time nothing to indicate they are actually Naturist), but one, I'll not mention the name, seemed very closed. Although their website indicates they accept guests as soon as you inquire about staying you need to go through an interview with them!? What is that all about!? We had no time for that, a pity as their location seemed very much in nature.
As to naturist friendly beaches, although there is some info on the internet with locations we have found that to be inaccurate at best. For instance there was supposed to be something near hot sands and hot springs (geothermal activities), forget it in real life, it's teeming with textiles by the 100's and lots of kids.
We did a bold thing and went on a Naturist hike through jungle to a water fall and pond, got some funny looks by some other groups of hikers and when doing the swim in the, freezing cold, pond surprised some other visitors, but all was well and no negative reactions. You simply have to be mindful when there is kids around. I know, we should not have to be but I also see it from their side. Let's face it, we all have different values and norms and we have to respect that.