I have gone to 1% once. Wasn’t intentional but just forgot to charge the car over night and only had enough time in the morning and risked it on the road knowing there will be plenty public charger on the way back should I need one. But as the miles rolled away, I was getting closer and closer to home so decided to leave it and see how deep I can get into the range estimate.Yep, I'm much the same - 80% is my normal charge level, but I've dipped as low as 4% on a longer trip. Granted, it did calculate 10% arrival state of charge, and so I started to nudge my speed up as success seemed more and more likely!
Turned out the cars range estimate was pretty good.