If Townsville were to get a new 30,000+ Seat stadium then I wouldn't be against them getting an OCCASIONAL game, I imagine 30,000 North Queenslanders could create an atmosphere to rival Suncorp. Gold Coast is an hour down the road so I don't think it's worthwhile.
Maybe they could add 1 game to a "regional" venue every 2nd 3 year cycle if there were stadiums in place to accommodate it (None currently big enough IMO).
Y1 - Brisbane, Sydney, Brisbane
Y2 - Sydney, Brisbane, Newcastle
Y3 - Brisbane, Sydney, Melbourne/Perth/Auckland
Y4 - Sydney, Brisbane, Sydney
Y5 - Brisbane, Sydney, Townsville
Y6 - Sydney, Brisbane, Melbourne/Perth/Auckland
Spreads it around a bit whilst still giving Brisbane & Sydney the majority of games. Once every 6 years would make it a "must see" for Townsville & Newcastle.