[Request] In a car, using the AC use more gas, but opening the windows increases drag, also using more gas for the same speed. Which one would use more ?

Just came back from 2 weeks vacations, traveling around 2300 km. As I'm a lowering window enjoyer, my gf prefers AC. I just assumed drag increase would be negligeable but tbh I have no idea

I dont want/need a detailed calculus, but in case context is needed : we're talking about window fully down at around 90km/h vs AC at 24°C vs 30+°C outside