Speed and elevation equals more energy. Elevation change and wind can really affect range.
The Speed and Charge
Always allow 30-50 miles of extra range in calculating the next charge. Keep up with the math as you progress and check that you still have that reserve. The algorithm seems to be taking in aggressive driving pretty well, but add a little extra room. Give yourself 30-50 miles extra over what the navigation recommends.
Another good idea is to stick to 65 miles per hour speed and use your cruise control. Check the weather because the cold weather will reduce your Model S's range, or the range of any EV, including hybrids, further.
Us an Trip Planner Help
Before your trip know if the range is an issue for your trip. For this you can use the EV Trip Planner, which is a useful tool for many electric car owners.
Go the route given by the map and maybe give an extra 5 minutes on each charge if you plan on speeding within the speed limit. "With the 80 MPH speed limits and elevation changes, you'll be asked to keep your speed lower to make the next charger. You may start out with 40 miles extra each time, but as you drive, it will drop to 20 generally and I believe you get better charge times when you have 10% still left in the battery. There were a few charging stations where there weren't any restaurants around to eat, just next to a hotel. So plan for that as well," recommends a Tesla Model S owner named Ben, who just got back from a long trip and shared his experience in Model S owners group on Facebook.
Check the air in the tires. Make sure they are at manufacturer's recommended levels.
Pay Attention to Autopilot
And lastly, if you are going to use the Autopilot, be alert and watchful. You must pay attention. Autopilot is designed to replace the driver, but to assist the driver to reduce the load. This miss this story in which an airline pilot and a Tesla Model 3 fan says it's laughable to put Autopilots in cars with untrained masses. Read why he says that.
Have a safe and fun trip. If you have other long trip planner tips, please share in comments and we all will benefit from your road trip planning tips for Tesla or other electric cars.