From experience I can say that I would have no worries about taking my Tesla and drive it from Copenhagen Denmark to Barcelona Spain, without spending one second looking at a map first to scout chargers.
Granted, south of the Alps, even the Tesla superchargers density are a bit lower but they works. And north of the Alps there's so many of them that you can decide by not just when you need to charge but which are located in a place with facilities(toilets, restaurants, cafe etc) you might need. And should a Supercharger destination be full(perhaps because of broken chargers although I have never seen many failed at one time), the navigation will suggest to go to another charger than originally planned because of congestion.
Furthermore, Tesla seems to be very aggressive about building out the charging networks. You might hear stories about people waiting in line at a supercharger, but what you don't hear is that if that happens more often, they will expand that charger, or build another one along that traffic corridor.
I have even seen them a few years ago have employees sitting in the show at Christmas to help people charge or something when there were a lot of holiday travels. Not sure why, didn't ask.
And I wonder why are no one else are being that aggressive about creating a functioning dependable charging infrastructure? Even Ionity(EU version of electrify America) with their EU grants, VW Dieselgate money and other car manufactureres are doing a worse job than Tesla without the EU grants.