For what it's worth, I believe I read an article on Reddit where people were theorizing that it is best to keep your battery as close to 50% SOC as possible for longevity.
With a full 100% rated range of 315 miles, that means every 1% of charge is 3.15 miles.
So, if you drive 4 miles per Kilowatt (250 watts per mile efficiency), and you drive 31.50 miles per day, you'd want to charge to 55% daily (for example). This will swing low to 45% when you plug in, and back up to 55% for the next day.
That being said, it's also a theory and also subject to "diminishing returns" meaning the perceived or actual degradation from charging to 100 vs. 90 is greater than the difference between 90 vs. 80, and so on.
When I eventually get my Model Y, with my daily driving requiring under 30 miles per day (commute is 20 round trip plus a few trips in town with kids & errands), I'm intending to charge to either 60 or 70%. This is mostly because I have 120V charging and it would take a really, really long time to get the pack up higher if I needed it for a trip.
(a 74 kW battery pack filled to 66% would take somewhere around 18 hours to full replenish the remaining 34%...)
74 kW @ 66% = 48.84 kW, 25.16 kW remaining; 120V@12A=1.44 kW*.8 efficiency =1.152 kW; 25.16/1.152 = 21.84 hours to fill the remaining 1/3. That means if you ran to 0% it would take you around 65 hours to fully charge.