For very long one-way trips, Superchargers
are enough almost everywhere: on such a trip even if you need a diversion to pass a Supercharger you can normally contrive to make it insignificant, since most long distance journeys have more than one plausible route and more than one possible Supercharger.
The problem comes at the end of your journey to recharge for the return (&/or local driving at destination). If you are willing to choose destinations based on charging (eg. pick hotels with Tesla destination chargers for preference) then no problem. In my case, our accommodation is usually selected on other factors (often by my wife) and it’s up to me to sort the charging. Often the UMC and a handy 13A socket solves the problem- hotels usually go out of their way to help you on this in my experience (and the exception was already in line for a bad customer service score before they refused use of a perfectly suitable socket).
But sometimes there’s no option other than to fall back on public charging. All networks are required by law to allow you to charge without requiring advance sign-up, most of them achieving this via a smartphone app to collect payment and enable the charge, an increasing number by accepting contactless bank cards. Those app-based are of variable reliability - mostly due to incompetence rather than malice, though Polar are very keen to make you join their monthly subscription plan and the inadequacy of their app might be more than coincidence. Having both a CHAdeMO adapter and a Type2 cable gives you many more options (and you will almost always need one or the other for public charging). A combination of
zap-map and
plugshare is usually sufficient to sniff out options. You do need to check before you set out (or alternatively spend a lot of time keeping up on the changing state of public charging and downloading lots of apps for new networks just in case you go to somewhere they operate.
In my experience, out-and-back or multi-stop circular day-trips are much more of a problem than long trips, being much harder to contrive a route past a supercharger than a one-way trip of similar length. For me, the CHAdeMO adapter is still essential to make those trips work, but this will depend where you live - my trips often start off cross-country rather than up or down the main motorway routes.