Chitry les Mines
On the Canal de Nivernais near Corbigny, on the Auxerre side of the Baye summit, there is a newish slipway that has been built by VNF at the Chitry les Mines Port de Pleasance, It was used by Keith Waller to recover his boat when the Yonne was closed at Clamecy due to flooding in 2016.
Keith Waller in 2016 says the contacts are John and Stephanie, who both speak excellent English.
Slipway is free
Storage is available in a yard for car/trailer. €3.30?
Train station at Corbigny 3km