We have never been saturated to this extent.
And while not lessening the importance of the republican question in Australia, the role of the monarchy and its impact is nothing whatsoever like the EU, though it might surprise you to realize I think Australia should follow through with that.
But aside from that - you are probably right about the EU collapsing - the question is to what sacrifice - it will catastrophic by that point.
There are certainly differences between the issues in Australia and the UK. Theoretically a Republic might not be a bad idea in Australia - unfortunately it's really a stalking horse for the left to try and create a more left wing state. But the main point as far as I am concerned is we were being told constantly and a lot of people believed that it was a decision that would stand for at least a century - that it couldn't happen again. Well, I'm seeing the same arguments in the UK now and I think they are nonsense - people do not have to accept this vote for all time. It does work both ways to some extent - if the vote does go 'Leave', I can see those who disagree with that trying to get Britain back into the EU - but that would require the cooperation of Europe as well.
Please understand I think it would be much easier if the Leave vote wins today. It will be a disaster if it doesn't as far as I am concerned and I am pessimistic, unfortunately. But I think there's a real risk that some people will feel such a high degree of defeat that they will give up - and I think that goes too far.