Well, I haven't checked that specific scenario, but I know at 47.2F average throughout a trip, with 16000 mile winter tires cruising at 82.6 mph, a 14.3 mph headwind, with a +463 ft elevation change, climate set with range mode to fan speed of 3 at 74F, DRLs on with a screen brightness of 73%, streaming radio playing at volume 4, i was averaging 325 wh/mi and got 231.3 miles out of a full charge. /s
JK.... being real though, at 80 mph you'd probably get about 230-240 out of a full charge in normal summer weather. 70 mph is right on the rated range typically so id guess 80 would have 10% less efficiency given the logarithmic increase in air resistance as velocity increases.