That is unlikely to happen during our (or at least my) lifetime. While they have make very good progress over the past four years, it's still a very long way from "only a maximum daily charge is required to travel anywhere in North America, or even just the lower 48". This is true in spades in winter when an 85's range drops to around 175 miles. And I'd guess that all the easy-to-obtain locations have already been taken, so it's going to be harder from now on to get each additional location.Making supercharging no longer free for new owners is almost certain to change charging behavior. I just hope the charging infrastructure (both superchargers and destination chargers) is in place so that no one ever needs to perform a 100% charge at a supercharger by the time our Model 3 starts shipping in volume.
The only other solution is longer range, in the 400-600 mile category. The technology isn't quite there yet but I'll bet that it's there long before all the SC locations are in place.