In reply to lummox:
There is a bouldering "circuit" next to the river in Mortagne but I haven't been there.
There is a crappy little 10 m bolted crag in Apremont but even the Chateau is more interesting.
I stay with friends near Le Poire sur Vie, and one of the featured and much hyped up randonees features the Pierre des Farfadets. It's a granite boulder in an admittedly odd situation in terms of its isolation but to read up on it you would think it was the size of a double decker. It is so small that on any Derbyshire crag you would vault up onto it to eat your butties.
Much as I like the Vendee, TBH it's a climbing desert (as you suspected, I suspect)
Better off hitting the beaches, picking mussels off the Passage du Goix or tracking down a shop that sells coypu pate
If you have kids, the Chateau du Puy du Fou will probably give them the most memorable day they have ever had in France.