Maximize longevity: buy the biggest capacity battery and it will last longer before it reach a minimum acceptable range for you to keep it on the road. I am not familiar with battery degradation but I know in flash memory it is every 15% extra capacity will double the life cycle. If you use 8% / year reduction for EV, every 32% extra battery capacity would last another 4 extra year. If you don't need that much range of a bigger battery, instead of keeping it between 20/80% keep it at 30/70% or 40/60%, but the limit is likely still going to be # of years even if you don't drive it.
Maximize dollar per mile spent: buy the most affordable mile range per dollar EV now, upgrade when it ages. By the time you upgrade you probably will see EV price drop already. Or upgrade when there is a huge discount but you have no control over when and whether that happens.
To me, I think buying a plug in hybrid and call it a day is going to be easier. 98% of my driving is within 40 miles anyways and I get to use electric, save the environment, without overpaying for that 2% I have to worry about.
