We are spending one additional night in Paris, about 24 hours, coming in on the train from Amsterdam, and flying out of CDG the following day on a 7pm flight. (We will have spent 3 days in Paris the previous week.) We are staying on the Rue Cler during our first stay, but would love different hotel/area suggestions for the single night that might be convenient to both the incoming train and getting to CDG. Or most convenient to the train, at least. We don't plan to do any major sightseeing that day, so it night be a nice day for walking around or biking, and eating and drinking...any suggestions would be welcome!
MK, I hope you don't mind my saying that anywhere in Paris ought to do and you should pick a neighborhood you'd like to visit in.
Paris is small and has a great transit system. At the same time you don't want to be too close to a train station, they are noisy!
At Nord you can catch either the 4 or 5 metro or RER B or D. Take one of them to a nice neighborhood that interests you. 5 goes to Bastille, for instance, on the edge of the Marais.
We stayed at Best Western Premier Ducs de Bourgogne once which was a charming hotel just a short walk from Châtelet les Halle's RER. You could leave your luggage at the hotel after checking out in the morning and then hop on the RER for the ride to the airport the next day. We have also stayed near Luxembourg Gardens where there is an RER station on the east side of the park and a quick trip to the airport. We recently stayed at Hotel Villa Madame on the NW corner of the park.