The new international Berlin–Copenhagen cycle route was announced end of March.
The cycle route is ebike friendly; you will find battery charging points in every 30 km. Check out the interactive map here!
Well, I’m a little bit envious of the German possibilities. Look at the cycling map of this region (click on the “i” button, and choose the “Radwandern” category). You can see there dozens of bicycle routes even 1200 km long! 😉