If you haven't already, check out Plugshare (online or app). It shows not only all the Tesla Superchargers, but any available chargers of any level/kind, so in case you are in a pinch, or are looking for a hotel with a destination charger it has that data as well. And the best thing is that it is user driven, where people will leave updates, tips, notes etc (like if a charger is in a lot with a fee etc - although I have usually found that if you are charging for less than 30 mins they will let you leave for free).
Good luck with your road trip, and be sure to post about your journey here!