If the current vehicle meets your commuting needs, do you really care if the new one has so much more capacity? To recharge it would either take twice as long, or, you'd be paying to have a bigger on-board charging circuit and a major upgrade to your EVSE (and many houses won't support that without major costs)...doubling it will mean more weight and costs. I looked at the i3 as a product that will have an extended service life - very little actually wears out, and it's not like the body is going to rust away, or you get a hole in the quarter panels. Unless you're one that always has to have the latest and greatest, I do not see any major safety improvements coming, so I plan to keep mine for longer than my normal purchases. When it gets old enough to consider a battery replacement, I'm sure that there will be options, and there will always be some turn-in value of the existing battery pack. Then, it will be a decision to either buy a whole new vehicle, or upgrade the existing one and, when you keep them long enough, the resale value tends to level off.
There's lots more that can go wrong on an ICE and maybe more reason to consider replacing them more frequently.