I have driven in many of Europe's highways and I wouldn't take an Enertia anywhere near them. It's suicide. I just thought it would be a nice alternative to scooters. For the actual roads, I wouldn't take them with anything less than an Empulse and even that would be risky. A Lito Sora or a Lightning would be more appropriate for that kind of trip.
I did 2000 miles in the Alps on a F800ST and wouldn't hesitate to do it again on an Empulse... much better handling bike for the hairpin turns. Just have to work out charging with the hotels at night... and have shorter kilos per day. Lovely, silent way to do some of the best roads on the planet.
Now I DO admit I wouldn't want to ride ANYTHING around those crazy Italian kids on liter bikes that come out on the weekends! My buddy said, "They don't obey the traffic laws." To which I replied, "Hell, they don't obey the laws of physics!" We saw two hit each other head on a straightaway. One died at the scene; the other removed by air ambulance. Insane. Sad. Darwin at work, I guess.