Welcome,
February 2003 is not that far away.
Seats going to Australia are very difficult to get as there are limited seats on those routes. On United, people often plan their trips 330 days in advance in order to get the seats they want.
If your partner has been travelling to the US a lot (which your note seems to indicate), he may have enough miles to get you and your son to New Zealand in February.
Good luck... and let us know how it goes.
William