I haven't yet had to wait for a supercharger, but I have seen full superchargers that I haven't needed to use. With the huge increase in vehicles from the 3's being sold, I expect congestion to increase before it's counteracted by more charging options.
I'll be pretty bummed the day I have to start waiting. Waiting might tip the scale for me from electric being a better roadtripping experience to gasoline. On the other hand, autopilot is pretty sweet.
I hope they don't fuck up supercharging like they've fucked up service. It's a necessary ingredient to a great overall experience.