I've noticed that range & battery usage estimates in the mountains are way, way off. It's not surprising since going uphill uses a of power while going downhill uses hardly nothing. I'm a bit surprised the Tesla range and battery usage estimates don't take this into account since it should be easy to compute. Very easy--it's simple physics that should work. Tesla can easily get elevation information along the route, or it can just use the vast data it has from existing car usage along a route. And this is vitally important. If usage goes up by 2x, the effects whether you can make it to a charging station in the mountains.