Your link shows that Southland is significantly colder than France for much of the year. No, the winters don't get freezing cold; it's not Iceland. But it never gets very hot either. Overall, it's colder than Western Europe.

Comparing "New Zealand as a whole" doesn't make any sense; the differences in the country are too large. It's like drawing conclusions about the climate of one state based on the United States as a whole (and even within some states there can be pretty large differences).