Combine into say 2 teams per main states, 1 tas, 1 act, 1 nt, the best of the local leagues. Relegate a couple more from div1 to div2 maybe. Then you would have a situation where each team in div1 / div2 could play each other twice during season.

Promote 2 div2s / relegate 2 div1s at the end of each season.