To math at it from a different angle, an AC compressor should need a low single digit kW amount to run... and unless you're parked in the sun in Arizona it's not going to run 100% of the time. If your average were 1kW, naive maths says a 75 should give you three days' worth of AC... a whole day if you average 3kW. Given that driving will empty the battery in probably less than one up to 29 hours... well, realistically, up to eight or so hours you've got 1-3 days vs 1-8 hours.Understood, good to see it's not a massive drain.

Another angle, it'll need 200-600Wh or so to do a kilometre. An hour of AC at an average of 1kW is *drumroll* 1kWh, 2-5km or so of range lost per hour.