If your criteria is health care then its not necessary to be near a big centre, as in Canada, NZ has public provided health care, because the country is so small hospitals tend to specialise. If you have heart problems and live in Napier / Hastings then I would expect that you would end up in Waikato hospital in Hamilton for anything that requires much more than basic care.
There are regional Hospitals in Northland and the Coromandel Peninsula as well so you don't need to be limited.
There is also a network to facilitate emergency transfers including ambulance, helicopters and air plane based transfers depending on how far you are going. You have to remember that the scale is so much smaller here that your never really far away from anything.