How do they feel about what's shown on TV5 on a Saturday and Sunday morning? That's presumably pitched at the full age range so maybe something will appeal?
From memory, there's Pacha et les Chats (animated puppets), Mila raconte mille et une histoires, Adibou Aventures (educational), Atomic Betty, Norman Normal, and something else educational whose name escapes me for the moment. Only problem is at least some of them are Canadian so I don't know how easy they are to get - though I do know Amazon.fr has Atomic Betty. SamSam and Inuk used to be on there too - though again, Inuk is Canadian.