"There used to be a 16 km viz, 3000' cloud base requirement as well, that is now gone and day VFR minima apply. I'm not sure I'd want to go VFR at night down to 5 km viz, 600' cloud base"
Not quite. NZ CAR 91.301 refers:
Table 4 Airspace VFR met minima - below 3000 ft - in uncontrolled airspace, clear of cloud and in sight of surface, visibility 5 km
controlled airspace - 2 km horizontally, 1000 ft vertically outside a control zone, 500 ft vertically inside a control zone; vis 5 km below 10,000 ft AMSL
Table 5 - VFR minima at aerodromes within control zone
Day and Night - 1500 ft base, 5 km vis
Table 6 - VFR minima at aerodromes in uncontrolled airspace
Day - 600 ft base, 1500 m vis
Night - 1500 ft base, 8 km vis