You could start with a gentle trip to Polch the home of your ARTO, we did this trip early last year stopping at Brugges and then Thieu in Belgium followed by Monschau in Germany before a drive through the Eiffel mountains and passing the Nurburgring to spend a night on the factory Stellplatz.
From the factory you can get onto the Rhine or the Mosel and make a nice trip with lots of Stellplatz as you go. We finished up in the Netherlands for the Tulips but it was early in the year.
now that is not a bad idea!... are the Stellplatz plentiful and easy to find?...do u have a link to a directory? Did u contact the factory first... mind u i dont think i could trust myself looking at all the new shiny vans....
Assuming you have a smartphone or iPad or both its worth paying a few € and getting the Campercontact app https://www.campercontact.com/en/content/app?fromsso=1