Just go yourself, its so easy. No tour busses, no fixed schedules. Its so easy, with on-line flights, hotels, AirBNB, etc...
When you get there, call people like this - they will give you great tours, at your own pace and schedule
My dream (2-3 years from now) is to head back to Germany for two months during the summer. Make that four years from now, when the Passion Play resumes in Oberammergau.
I'll rent an apartment near Traben-Trarbach, the town I lived in during my tour in Germany. Weekends will be for winefests and local excursions. Monday is always the best night for winefests: the tourists are gone, and the locals let down their hair.
Tues-Fri will be for trips outside the area: Amsterdam, Munich, Hamburg are a four hour drive away on the autobahn. I will also devote a few travels to Italy.
Sure, it will be expensive, but my youngest son will be freshly out of HS, and my grandson will be 10.