We arrive in Paris on May 1 and know it is a national holiday. We want to reload our Navigo Decouverte. I know there are machines however we would like it done in person to avoid errors. Is there a way to find out what booths are manned on May 1? We are staying in the 5th, Rue Mouffetard. The closest Metros are Censier Daubenton and Monge. We can go elsewhere if necessary.

I don't think so. ReR stations might be more likely. Do you speak French well? I just would not assume having a person do it would be less error prone, could be worse. The machines have English options, you know.

Yes, the machines are in 5 languages.