In the NZ context, I'd go for the option of starting all over again with the five franchises plus NZ Barbarians (made up of wider training group and U20's players). Home and away schedule, with the Barbarians matches taking the place of the bye as an exhibition match played every Friday (e.g. wouldn't count for competition points), and the two competitive matches played sequentially on Saturday afternoon/evening. Standard Super Rugby competition points and BP setup.
Guess you could end it with a final between the top two qualifying teams, and follow it up with a North Island vs South Island match/series. Hell, maybe even a good old fashioned Possibles vs Probables.
Assume Australia could equally do something similar, if they so wished.