We did Port Macquarie from Roseville in Sydney recently, mostly using the adaptive cruise and keeping below the limit, and arrived with 13% to spare. We charged up at a friend's cottage on the Port, and it took 2 days using the UMC, so we might try Harelec next time. On the way back we experimented and found that going at the limit or better made almost no difference to the car's expected end of trip stored energy surplus, so we sped up and kept up with fast lane traffic, but still on cruise. Again, 13% to spare. I think this is where the Tesla low drag really counts, but avoidance of unnecessary acceleration by using cruise also ensures a comfortable margin. I wouldn't worry at all about Sydney - Port Macquarie as a trip in the future. Let the cruise control take the sharp acceleration out of your driving pattern. We live 6 km from the St Leonards supercharger, so could have made that from PM easily.