Our large family (7 kids) met up with my parents for a week in the Missouri hills, and we were not disappointed with this house. Lots of space for kids and two couples. The bunk room worked out great for kid space, and we loved having enough dining table space for all of us! The space to run, the swing set, looking for cool rocks in the creek bed, and visiting the horses were all highlights.
You will be driving on dirt roads, but our 15 passenger van and my parents' low clearance hybrid both managed without trouble because it's pretty well maintained.
Our only issue lay with wifi that was basically nonfunctional, but the host did give us a heads up, and I expect it's been handled. Would highly recommend this place for large groups looking for a quiet retreat in the Ozarks.