You forget one minor detail... any suitability specced Model S can be fast charged for free, for life at any Tesla dealership/service centre/supercharger point 
The batteries also have an eight year, unlimited mileage warranty. Which is nice 8)
By the time they are half that age they'll probably struggle to get you to the local corner shop. 
Are you sure about that?
There is a taxi firm in Amsterdam that has been using them for a while. My understanding is that Tesla offered them a *very* good deal on the cars in exchange for telematics, range & charging data. A way of getting accelerated miles on the cars if you will, while also testing the durability of other components such as door handles, interior trim etc. The battery data collected is very interesting.
I think the full study is linked in the docs on the website but
looking at the trend lines on this webpage would indicate that after 90,000 miles, around 94% of the vehicles range remains. Or that the original 265 mile range (with most users achieving 240-250 in temperate climates) would be around 247 (or 227-235 in the real world) miles. Hardly a catastrophic loss.
If I am in the market for a new car, I will seriously be looking at the model 3 when its comes out in 2018. Assuming it meets its target price of around £35-40k and has the same warranty. An 8 year usage of 160k would save around £18,000 in fuel over a 45mpg diesel. And would probably have sub 6 second 0-60 time to boot. More importantly, it allows for a very quiet ride and never needing to queue up at a petrol station behind a queue of people each putting £4.87p worth of diesel into their cars!