If the 6N can give Georgia more games - similar to Argentina playing Uruguay, Chile and Brazil then things could really be shaken up. Georgia are a heck of a lot better than the three mentioned South American teams. 15-6 vs Scotland in the World Cup is pretty clear that things have to to change. Georgia are the new Argentina - i.e. a team with no competition.
A Euro competition could work and I think Northern Ireland would get the green light surely. 10 teams in two pools with the top two advancing to the final and the second and third playing Semi Finals. Have it every four years. USA IRB World Rankings to distribute the pools. The top three from the ENC Qualify.
Pool A - England, Northern Ireland, Rep. of Ireland, Russia, Italy
Pool B - France, Georgia, Romania, Scotland, Wales