When it comes to rugby, your partner will have no problem finding a team to join. Even in the most rural areas, there are rugby clubs. What I would do is find out which clubs are in the areas you are thinking of moving to and then find out about their various programs. Often, in rural areas like the one we are in, if there aren't enough players for a specific level, a few clubs will combine together to field a team. A lot of clubs do a weekly drop in touch night and that is a good way to scope a club and find out about the different ones in your area. Your partner will have to take what they might say about rival clubs with a grain of salt because they sometimes are fiercely loyal to their club (even if they played on the rival team due to lack of numbers).
My husband recommends checking out a Marist club in your area as they are an organization that is nationwide.
http://www.maristrugby.org.nz/clubs.html
If you find a good club, rugby is a wonderful social event that connects you to the wider community.