Having a 6 nations tournament both here with England, Ireland, Scotland, Wales, France & Italy
Making sure we have a GB tour thrown in every once in a while so that the home nations players dont all hold out for England.
Also on the Southern Hemisphere having Oz, NZ, Fiji, PNG, Tonga and Samoa.

The next 6 highest ranking teams left also having regular tournaments.

There's an appetite for the game so lets do it.

Year 1. 6 nations Northern/Southern hemisphere
Year 2. 6 nations top 3 from each of year 1's tournaments in one hemisphere and the the bottom 3 play in the other hemisphere
Year 3. WORLD CUP
Year 4. GB tour.

I think that could work

Maybe a Northern hemisphere team v Southern hemisphere team as part of a tour