A sabbatical for my 7th grader - distance learning

My son is a Montessori kid, and always has been.  He's very good at independent and group work, and often follows his interests very deeply and for a long time.  Of course, he also has entire subjects and disciplines that he would completely avoid without teacher guidance.  He's not usually challenged in school, but he's a creative learner and generally manages to complicate things enough to keep himself happy and learning - or else we do that for him. 

One way we want to challenge him is to take him out of school next year for several weeks at a time on multiple occasions and send him to various friends and relatives who are experts at different things (carpentry, painting, geometry, anatomy, etc.).

I'd love to discuss ways to make this sabbatical rigorous, exciting, not-difficult-for-the adults, less-disruptive-to-his-social-development-at-home, etc.  This is somewhat a "distance learning" issue and somewhat a "what am I not thinking of" issue. I'm not too worried about all the district approvals and things like that; we've done most of the groundwork.  I'm more interested in talking about how to make this experience better than if he just went to his (pretty good) school.

Thanks!  Any discussion is welcomed!