In reply to snoop6060:
> There is a sector up high (that I can’t remember the name of) that I think stays dry in all weather. The approach is really good fun and likely quite exciting in the pissing rain! Starts with a Tyrolean over the river.
Secteur Hulk, which would be a reasonable option. Probably dry once you're in the cave and there are some routes to do at the OP's grades. The easier routes are decent but short and mainly on the right of the cave which is less sheltered and might get wet if the wind was in the wrong direction. The via ferrata approach takes you through some spectacular rock scenery and would require focus in the wet.
Exploring the tunnels and the Sentier Martel would be another wet-weather option.