I charge based on my estimated usage pattern.
In my S(software limited 60) i charged 2-3 times a week to 100%.
In the 3, the range and efficiency has been ridiculous. I charge to 70% on Sunday and that is sufficient for my commute Monday-Friday. On Friday i charge to 90% and that is enough for my weekend excursions.
On travel weekends, I charge to 100% and go. Don't need to supercharge to my normal travel locations 250 miles away.
I have supercharged on one trip to Canada which was a 6 stop long weekend. Supercharged at 115kw, which was amazing. Left supercharger at what the GPS trip planner told me +15%
Overall much less charging than my S60D