heading to Tassie in the heat

Hello all, I am heading off in our Syncro to Tasmania this Saturday from Western Australia and will be driving in 40 degree heat for a few days as I head across the Nullabour.

I have done all the maintenance and will be carrying the spares.

any tips on driving in the heat for long periods would be welcomed.

driving speed, A/c on or off , decoupler on or off etc.

Thanks in advance Greg