There is no such thing as a frozen ATPL within the New Zealand system.
You may want to check out the current status on the validity of the exam credits that you have. There has been recent changes to how long they are valid for, the length of validity depends on when you did the exams. In some cases the validity period has been reduced. i.e you may have had ten years when you gained the credit but this could now be reduced to less than ten years.
Which ever way you go there will be plenty of hurdles to jump.