OP
Studying for a nursing qualification to work abroad after many years of education seems pretty drastic unless this is a career choice your partner would seriously consider in the US. There is a reason there is a shortage of nurses in many countries - the pay is pretty low for a high hassle job. Lots of nurses from countries like the UK and NZ move to the US and are very happy there - there is a reason for this!
Have you thought about other alternatives? Could your partner complete his doctorate in NZ whilst you get a job? I'm sure that you are used to living cheaply if you haven't been running up debts for the last few years. He should be able to find a job of some kind (tutoring?) to bring in some money and experience the local culture.