thank you for your clear instructions.
Will the service disruptions described above also affect the RER B route from Paris-Gare du Nord to CDG ?
Thanks in a advance.
Yes, unfortunately both directions of RER B between CDG Airport and Paris will be affected by the Paris trains service disruption, from Paris to CDG and CDG to Paris.
The Gare du Nord RER B trains heading towards CDG will depart from surface level, on the Grandes Lignes level, and will terminate at Aulnay-sous-Bois station. From there replacement buses will take RER B passengers to CDG terminals, but the travel time is significant, between 30-45 minutes for Aulnay-sous-Bois to CDG Terminal 1 & 2, not including wait time for the bus to depart.