With the server upgrades and PS3 going the way of the dodo, we already know Stormblood's main city is twice the size of our current ones (because its not split in two). Maybe this improvements would also allow this idea to work. While its not "infinite" wards, it would quadruple the number of houses available on every server.
What if the map for a single ward looked something like this?:
It quadruples the number of houses without actually adding new wards, assuming the Stormblood improvements could make it feasible. Couple this change with a restriction of owning one house per account per server, and it would probably do a lot to make housing available to people while also preventing those drowning in gil from monopolizing all the land.