Air New Zealand is an airline that has historically been pretty stingy with making premium cabin award seats available, at least for travel to the U.S. That probably largely has to do with the fact that they had a monopoly in the U.S. mainland to New Zealand market. Fortunately in the meantime both American and United have started service to New Zealand, so they have some competition, at last.
Last year we began to see some Air New Zealand award availability out of the U.S. for the first time in a long time, though we haven’t consistently seen space since then.
Well, at the moment Air New Zealand has a good amount of business class award availability between the U.S. and New Zealand. A majority of the space seems to be available between May and the end of September. Admittedly this is winter of New Zealand, though it can be a beautiful time to visit. I visited New Zealand in winter about a decade ago, and had an amazing time.