The 'ANZAC' is a special ride, not unlike many other IBA specific rides around the world and pose many challenges for those wishing to attempt any of the rides. The more 'traditional' IBA rides can be attempted almost anywhere, (subject to rules) and wording reflecting specifics of the ride can be tailored into the certificate.
Distances and challenges, tell me about them. To knock off the East coast 50cc requires (me) a transport leg exceeding 3,500k's, 2,500k just to get to the starting point. Multiple 50cc's on a 149cc bike required 400 kilometres just to get to the starting point let alone the 3,500k to get home.
These are challenges we Australians are renowned at addressing, we never say it can't be done, rather find a strategy many make it happen.
We have some special challenges in NZ that we are currently working on, they don't have any towns on either island commencing with 'Z'.
Now, we are planning a ride in November that may work for you?
https://forum.ironbutt.org/index.php?threads/centenary-of-armistice-2018-ride.1994/