You are right, and checked back, La Defense -> Chatelet is 9.4km (that's the two RER stations left open after shutting down CDG Etoile and Auber. And they basically shut down anything between these stations)

They shut down 36 stations in total at the peak of the demos: https://www.lavoixdunord.fr/502926/article/2018-12-07/la-rat...