When to travel the plenty highway?

Thanks for your opinions guys. I think I will keep my eye on road conditions for the next month to give me an idea. Then I guess we will just go ahead and plan the trip, and hope we don't have to go via Mt Isa when the time comes!

The central Australian tourist centre say that the rain isn't seasonal, it could come at any time of year, which makes sense because I remember seeing the Todd river flow more than once through the winter months!