4% degradation after 14 months, 19,500 miles, 700 to 1500 mi road trips almost every month, sometimes 2, so supercharge a fair amount.
Charge to 60-80% daily, normally from low of 35-50%. Mix it up a lot, but usually 65% is the limit.
Before road trips, we charge to 90-95% overnight, to 100 the hour before we leave.
Winters are cold, we go months in the teens and 20's, rarely breaking 30°F. I keep it plugged in and precondition before driving every day.
Every summer weekend we drive to the cabin 80 miles away, charge to 85 the night before.
I'm guessing the variety of charging, weekly 85-95 overnight and frequent trips below 20% are doing more to keep the apparent degradation on the lower side, just keeping the BMS calibrated.