Wonderful 3D fun, starting crouched at the very back of the roof. Climb the roof with creative foot jams, and romp up the arete in big moves between big holds.
Rain sucks, but broken holds suck even more. Remember, never climb on wet rock in Fontainebleau.
The sandstone becomes brittle, and pulling on it will ruin classic problems. Drying it doesn't help, because it's still wet and weak inside.
All you can do is wait for better conditions.