Yep, join ChargePoint. I keep the swipe card in my glovebox to make sure I have it.
A couple of small clarifications regarding the public HPC chargers. Yes, most have been updated to J1772, but I am aware of two that have not: 1) The Stanford Ranch Office Park location in Rocklin, CA still has a Tesla HPC. I believe that there is also a J1772 charger available. Jack Bowers, a Tesla owner, install the chargers and plans to keep the Tesla HPC until it is no longer necessary, and 2) the ClipperCreek building in Auburn, CA has both a Telsa HPC and 75 amp J1772 outside their business. You need to flip a switch to the one you want to use (very obvious), so not two charging stations, just two options there.
The J1772 cable cannot currently deal with any signal over 70 amps and will give an error code and not charge the car. I discovered this when I decided to test out my new J1772 adapter prior to a road trip, so I drove over to ClipperCreek for testing on the J1772 there. When we dropped it to 70 amps, there was no problem. Both ClipperCreek and Tesla are aware of the bug and I have emails indicating Tesla will update firmware (yet again) when they have a bug fix, so that J1772 stations over 70 amps can be used. (The good news is that it is extremely rare to find a J1772 over 70 amps. In fact, it's unusual to find one over 30 amps.)
Roadtrips: RV parks are everywhere - the UMC 14-50 is the only adapter I'd recommend. I also carry the 120v connector - I've never been at a hotel that doesn't have some outside outlets. While it doesn't seem like much, it does add up to 40-70 miles overnight. The two times I've done that, I've talked the valets into letting me park it in their protected area, where they can watch it.