Yes, I've thought the Dordogne and Lot valleys in France would be a great
place for a family vacation -- with canoeing / kayaking, hiking,
sightseeing.
http://roberts-1.com/t/b02/france/doi
The children I ride with have _no_ interest in being forced to bicycle every
day, so I would have to make a plan that includes lots of other activities.
Renting a van would be way cheaper than than some guide service.

The big problem is that lots of _other_ families with children already know
about wonderful regions like that -- so I'd be concerned to find a time when
it's not crowded -- and hot. Like not August. I think the ideal would be
to somehow take the kids out of school for a week in late September /
October.

Ken