So Coastal v CTFC or are Dunedin sides possible?
Depends on how NZ Football 'read' their own rules for the cup draw:
4.3 The draw for the rounds involving 32 and 16 teams (Rounds 3 and 4) shall so far is practicable have due regard for the costs of travel for participating teams, and desirability of promoting matches of such importance throughout New Zealand in order to maximise local and community involvement. For clarity the practical application of this regulation means that teams from within Regional Associations 1, 2 and 3 could be drawn against each other, as could teams from Federations 3 and 4, 4 and 5, and 6 and 7.
4.4 The competition will become an open draw from the quarter final stage