Not got direct experience of that part, I went from Flensburg -> Als -> Fyn -> Copenhagen
But I'd check the Shelter app now to give you an idea of what's available - they have quite a few free wild camping spots with pretty good and secluded wooden shelters that you could peg your route around
As I recall the Rostock ferry isn't too cheap for passengers either? Rugen and ferry to Bornholm/Trelleborg is another option
Not got direct experience of that part, I went from Flensburg -> Als -> Fyn -> Copenhagen
But I'd check the Shelter app now to give you an idea of what's available - they have quite a few free wild camping spots with pretty good and secluded wooden shelters that you could peg your route around
As I recall the Rostock ferry isn't too cheap for passengers either? Rugen and ferry to Bornholm/Trelleborg is another option