Hi I can understand your fears.Have you thought about contacting someone in NZ from the industry that you would work in, perhaps via Skype/email, that way you would at least know what kind of money you would be earning. Are you used to being frugal or plenty in the pocket.? You say you have been working 70-80 hours a week, that's a lot of hours, I wonder what the difference in wages would be if you did the 40 hours.? Would you be prepared to work less hours (less pay) to have more family life.?
I guess that's what you would have to ask yourself.
I would agree.What kind of lifestyle do you have now, what are your preferences (are you outdoorsy, for example). You have to look at your own life and see what fits.