We went to NZ and Australia in winter of 2002 (we were in Australia for the winter Olympics). Right after 9/11, no American tourists but lots of Europeans, and Asians, especially Japanese. Things will be different now.
But what really made our trip were two books: Let's Go:New Zealand and Let's Go:Australia. They are basically student/budget traveler oriented, and we found lots of good advice and ideas in those books. We drove all over New Zealand and the East coast of Australia (Port Douglas in the North to Sydney). We were lucky in that the Canadian dollar was strong versus the Australian and NZ currencies, but the prices we paid would have been reasonable in Canadian dollars too. Plus we found all sorts of places to visit that were low cost or free. We had a marvelous time, we did not feel deprived because we did not follow all the standard touristy things. Some touristy things we did do, including fishing on Lake Taupo, but that was semi-mustachian because I caught our lunch. With a rental car we had total control of our time - heavy rain on the Queensland coast and flooded roads? Great - another day diving on the Great Barrier reef before we head South, we had our own snorkeling gear with us so no issues).
We were 2+ weeks in NZ and 3+ in Australia, and could have easily done twice that. I feel our time in Australia was like the Aussies and Kiwis we met who said they had been to Canada - and never got east of the Rockies. We never got 100 k into the interior. Australia was like being home in terms of the driving, 500K in a day was not unusual. People would warn us about the long drives,and we would say, it's just like home, Montreal to Toronto is longer - and they would say we would be fine, just watch out for kangaroos on the road. Lovely places, very welcoming to visitors, and lots of congratulations on our two hockey gold medals. They were very good about foreign accents, could tell the Canadians from the Americans.
They are great places to visit, you should have a wonderful time.