Wassailing didn't really make it to New Zealand except in the form of Christmas caroling which, when I was a kid, (50 years ago), involved the local church choirs going from house to house.
Nowadays even that has died out and the only ones still out there seem to be the Sallie Army, sitting on the back of a truck, just driving slowly through the streets.
Wassail songs, however, can often be heard late at night at NZ folk festivals or Morris gatherings, winter or summer, Easter or New year. They're no longer attached to any particular date on the calendar, but just sung because they are good songs.
The revival is alive and well and living in NZ!
Wassail!
Robyn