Tesla doesn't have public plans to install more than a hundred or so of the Superchargers in the future. There are already way more CHAdeMO chargers...
It couldn't be easier to use the Modular EV Power unit from a J1772 plug to a NEMA 14-50, then a common 6/3 extension cord as long as you need, then...
I read somewhere that the Tesla UMC was polarity sensitive at 120 volts... ok, that's not polartity, but neutral to hot sensitive. I have no idea if...
Be careful with your public charging per hour estimate of miles. First, virtually all are limited to 30 amps, and secondly, any in public commercial...
I hate the brittleness that happens to the copper from soldering. But, there shouldn't be much movement or vibration, so I think it will get soldered...