There are a ton of areas with no area Porsche dealers.

There are also a ton of Porsche dealers that are near major interstates.

All three of the closest Porsche dealers to me are on a plausible cross-country route on I-90, and if you are coming from east of Chicago up towards Minneapolis you are guaranteed to come very close to at least one of them. (Admittedly, you won't hit all three, and if you pass by two they'll be close enough that it won't make sense to stop at both. There's another one or two in Chicago. Going east on I-80, you'll come pretty close to one near Cleveland. If you go on I-90 up through Cleveland, you'll come relatively close to a second. If you keep on I-90, you'll pass very close to another in Buffalo.

Etc.

I don't understand why everyone seems to be focusing on how convenient the chargers will be for regular use. A lot will be convenient for road trips, which is when supercharging is most important.