Hi Zoe,
Certainly a challenge when 100% of your market has gone and a difficult problem to to solve. Maybe just a couple of ideas to think about..
– Under lock down it is very difficult to action this but could you change your business to target local Chinese speaking residents of NZ and sell them domestic holiday packages? Many NZ tourism operators have limited Chinese language capability and don’t target the Chinese market and certainly not the Chinese NZ market.
– Could you try to build a database of local residents using local Chinese media (Skykiwi etc) and social media groups now? Maybe offer a prize of incentive to gather their contact details then target them with offers of domestic travel ideas later.
– You could also use this to sell outbound tours and flights in the future.

Just a couple of thoughts anyway..
Best of luck