I mentioned this earlier, but if the teams get booted from the domestic leagues, then the Super League becomes what it's already intended to evolve into -- a new league.
The 5 "open slots" would become five permanent new members (but the SL doesn't know who that will be yet; the "open slots" are auditions for revenue generation/ fan interest in the current iteration I believe). 20 sides, 57 matches (each team plays each other team once at home, once away, and once at a neutral -- probably off-continent -- venue, to drum up offshore fan support), then 8 teams make the play-offs, and then there are play-offs to determine the champion. Plus there will be a random draw Cup of some sort.
Presto -- 70-odd matches, with not a drop of revenue shared with anyone outside the 20 Super League sides.
If it were just 15 clubs -- which I think would be the case if the SL were forced to start up immediately via expulsion -- then it'd be two home/away (56 league matches) and save the offshore matches for when the league expands to 20 later.