That's weird. Seattle-to-Yakima at 70 mph average speed and 85 mph peak speed is about 1.5x the normal energy use for me (260 Wh/m vs 350 Wh/m). Leaving me with 20% of charge when starting at 100% (260 miles): https://imgur.com/a/Dhs38kJ

And this was during the wintertime, so with a reasonable amount of heating.