If the Libs could stand on their own then the Nats would become irrelevant.Not sure I agree with this part of your post as the Nats have performed very well Federally, in Vic and also today in NSW.
I can't see country Australia changing their voting behaviour for many, many years to come.
They only get votes because they have a voice within a coalition. Take away that voice and suddenly they can do nothing for the electorate.