I can't speak for NZ, but in AU domestic tourism has more than picked up the slack - domestic tourists have spent more money than international tourists
When Auckland is locked down, Queenstown is a ghost town, but otherwise (50 out of last 52 weeks?) we've been pretty busy actually.
So much so that the tourism spokespeople who railed against the first lockdown are saying "Lets lock down hard so we can open up again faster" this time.