These aren't bad questions.
I also plan to keep my car for 20+ years. I have a 2014 Model S, so it obviously has the NCA battery. I knew more of the general things like not sitting at extremely low or high states of charge for a long time. Some of that more recent data I've been seeing from people here about keeping the car really near 40 or 50% to be most ideal sounds fine on paper, but I'm just not going to do that, because it's kind of an annoying and impractical way to use my car. I think this is where the 80/20 rule in life applies to this as well as most things. I am getting a reasonable amount of benefit by doing what is mostly good and avoiding the worst case treatment of the battery. That is good enough without having to stress and worry about it all the time.
And my wife and I recently had a talk about battery replacement or car replacement. With wk057 coming out with the battery warranty plans for older cars, we talked about should we get that warranty? Should we sell this car while it still is working perfectly before the battery fails? We came down to that I really love how this car is. It is grandfathered into the permanent data plan and permanent Supercharging. And we are going to keep it for as long as we possibly can, so we will just go with whatever comes--not get the warranty and probably just do a replacement whenever it happens. And we decided to go with the other way--keep this 2014 Model S and replace the old 2005 Honda Civic Hybrid with a new Model Y.
My daily driving should typically be 50 miles with occasional longer drives. Keeping to a 20% DOD should be no problem and charging to 50 or 60% whatever isn't an issue. I feel since my driving is kind of minimal, as in not many long commutes, I have a lot of flexibility in my charging options.
That's pretty cool about the grandfathering part. I think it will be interesting when battery replacements become more commonplace and hopefully not so expensive. I thought about replacing both cars with EV's, but that's a bit too bold for me . We like to do camping and need at least 1 ICE vehicle around for more remote trips. Definitely would like to try camping in a Model Y once though just for fun.