Bubu, welcome to MoveToNZ.
I know a lot of people go to NZ on Visitor's Visas and apply for PR once they are there, so I'd imagine you're just one step ahead of them in that you've already started the process. However, you would just need to be very careful to alert INZ that you are moving and make them aware of your new address, although probably you won't know that until you arrive in NZ.
Timing would be particularly awkward because of the indefinite date that your ITA package will arrive. If you hadn't already booked your tickets I'd have recommended waiting until you'd at least received the package, in case its arrival clashes with your departure from the country.
Perhaps a word to INZ would be appropriate to see how this could best be managed as they are the ones who'd have more idea about when you're likely to be sent your ITA.
Good luck.