Zero times. The question confuses categories:
You cannot "fit a country into a province"—they are political, not geometric, containers. However, geographically, New Zealand's land area (~268,000 km²) is about 28% the size of B.C. (~945,000 km²). You could fit ~3.5 New Zealands into B.C. by area.
But the premise is flawed: countries contain provinces, not vice versa. New Zealand has its own regions (16); B.C. has regional districts. Both are stunning, mountainous, coastal, and sparsely populated relative to size.