It's been hovering in the 90s to a bit over 100F where I work for the first time since I got my LR RWD Model 3. On the hottest day so far, when I got to work at 8:30am it was already around 80F and it peaked at about 105F during the day. When I left work at around 6pm, it was still in the low 90s. I had cabin overheat protection with A/C on and I noticed somewhere around 18 miles drained, which translates to about 6% in my case.
I have 20% F1 pinnacle ceramic tint on my rear windows and rear panoramic. 50% on the front windows. No tint on the front panoramic and no tint on the front windshield, but I do use a HeatShield sunshield. I also had 2 windows cracked just a little bit. Also, I have the black premium interior. Also, there is absolutely no shade where I park.
That was the worst day. When it peaks in the 80s, I noticed around 8-12 miles drained. When it peaks in the 90s, I noticed around 14-16 miles drained, so it seems to be pretty linear with temperature in my case.
Overall, if you can spare the range, I definitely recommend leaving cabin overheat on with the A/C. Even on those scorching hot days, it was relatively pleasant to get into my Model 3 with the cabin hovering around 100F, especially compared to my old car where I could barely touch the steering wheel when it got real hot. One drawback though is the vinegary A/C related smell when I get into the car, but it goes away after a few minutes with the fan on. I heard they may fix this in an upcoming firmware update.