You could also get a telstra pre paid overseas pack before you go.
I recall that the big cities in NZ like Auckland and Wellington have free wifi and there's is always McDonald's.
I don't know if Kiwi hotels are like the penny pinching ones in Australia who always want to charge.
I beats me why you can get free wi fi in a B and B in Cornwall or a safari lodge in Botswana or a motel in Geraldton but have to pay in a Travelodge in Sydney.