1. Tesla's check issue over the air, Telstra network coverage is fairly good on the busier roads. If the problem needs a technician go to next stage..
2. backload the car onto a Mackmuncher and get it to the nearest capital city.
3. Tesla tech will correct issue, the odds are high that he's up to date and prepared.
The concern of the car having a mechanical/electrical issue are low compared to having a tyre failure, windscreen damage or worst still a stray animal confrontation, all are possibilities and have to be prepared for, use quality tyres, carry a spare, take plenty of water and keep in mind that you may lose a few dollars in getting your car transported.
Don't let the above deter you from travelling away from built up areas, it's a great experience.