I have only ever had to wait at the busiest chargers and they are all in high population density areas, not in the mountains. Even then I have never waited more than 20 minutes.

I have driven and charged my car at Tesla stations in Norway, Sweden, Denmark, Germany, Netherlands, Belgium, France, and the UK and I think there are only two Tesla chargers that I have had to wait at: Lier South and Lier North, both just north east of Drammen on the E18 on the way to and from Oslo respectively.

The situation is not so rosy if you can't use a Tesla but this is only a problem for me when I visit the UK because of the very uneven distribution of Tesla chargers. However number of chargers, both Tesla and others, is growing rapidly almost everywhere in Europe so the problem is getting less acute.