'Mario Kart said:
The issue with an unihabited island is that no infrastructure is set up. There needs to be some kind of farming or sustenance set up so the survivors have an advantage.
Islands like Hawaii or Iceland would be best. Sure, there are zombies there but the plane that is taken with a cache of weapons could take over the islands. Start on the small island, clear it, move to the next one, cautiously but systematically. With patience, canned goods brought from the mainland, weapons, ammo, it could be done. This method is what would need to happen to overtake land again. Get some good sharp shooters and lure the zombies to the beach and shoot them from a boat. That's the way to go.
You've split the difference....at least in regards to WWZ. Part of the US government operates out of Hawaii....so it isn't bad. Iceland is the most infected place on the planet.
I've never read or wiki'ed WWZ. Just saying. In a world infected with zombies, I don't see how Iceland would be bad unless the germ originated from there.
On the other hand, I would look to inhabit Hawaii and clear it of zombies. After a decade or so, with conservation, and with Hawaii being secured, I take a party out and head for New Zealand. It is a least closer to other islands and more importantly closer to Austrailia. Yes, Austrailia will be infected with millions of zombies however given 20-30 years, kids will have grown up and my party is larger.
Two methods. If we are able to retrofit a cruise liner or ferry of some kind, dock in a port, lure zombies to said port, tease them into the. Oat and set sail to some other island that will be the "dead zone". Rinse, repeat for years with multiple ships doing this and Austrailia will. E clear of zombies. Sure, there is a need for fuel and reconnaissance for fuel will be a high priority. But, that leads us to option two and that is killing zombies with weaponry and so forth. Give people a couple more decades and living in Austrailia will be free of zombies. Do this all across the pacific rim and in a couple generations, the pacific islands will be habitable.
As far as clearing the mainland continents, that would take many more generations and many more reconnaissance missions for fuel, food, weapons.