California has way more SuperCharger sites that the rest of the country, so probably one of the few places it could even be an issue.
I just visited my first SuperCharger, and it wasn't even powered up yet (East Greenwich, RI). It's 52 miles each way from me, so about 45 minutes each way, not to mention an hour or more at the site, then, I'd use 104 miles of range on the round trip... Not a usefull endeavor, as you can see (2.5 hours of time and down 104 miles). The next closest SuperCharger is supposed to be in Portsmouth, NH, that's 75 miles each way from me... Nope, I can't see this becoming much of an issue at all.