If Origin moves to the end of the year and we use June-July as a window for an International series, Rep football will boom.
If Origin is October, the challenge is how to fit northern hemisphere nations into the calendar.
In your thinking, would June be a window for "Pacific" tests (eg NZ v Aus 3 match series, Pacific 4-nations etc without NH countries), then Origin in October, and Australia v England, Great Britain or France in November?
I suppose while Origin is being played in October, the Kiwis & Pacific Island teams could play each other in some other configuration (different to June) or tour/host NH countries, before one of the NH countries plays Australia.
To have a decent off-season after it all ends in late Nov, you may need to start the NRL season in late March though.