We do offer small group excursions on rare occasions.
Those are very small, averaging 3 to 5 bikes with 4-8 people, guide included.
The exact circumstances, the stretch we do, the timing and scheduling vary and can be changed. We have created a forum in German and English to allow for more convenient exchange between the members of such a group, prospective participants and us.
Please check it out here, you can read everything but in order to to participate in the exchange you need to register.