Close to IPN
- Hotel d'orsay at Orsay
RER B station : le Guichet (from Paris, one station before Orsay-Ville)
5 minutes by walk from the station AND 15 minutes by walk from the IPN Orsay.
https://www.orsay-hotel.com/?lang=en
- Hotel Le Village at Gif sur Yvette
RER B station : Gif sur Yvette (from paris, 3 stations after Orsay-Ville)
http://www.hotellevillage.fr/en/
- Residhome at Bures sur Yvette (about 20' by foot)
http://www.residhome.com/residence-hoteliere-aparthotel-buressuryvette-183.html
Massy- Palaiseau station (the most convenient place from our point of view) :
1/ Residhome de Massy
http://www.residhome.com/residence-hoteliere-aparthotel-massy-147.html
2/ Aparthotel Adagio
https://www.adagio-city.com/fr/hotel-8696-aparthotel-adagio-access-paris-massy-gare/index.shtml
3/ Mercure
http://www.mercure.com/fr/hotel-1176-hotel-mercure-paris-massy-gare-tgv/index.shtml
Paris downtown
You can choose hotels nearby a connection with RER B network. For information, Orsay is about 35 mn by public transportation from station "Denfert-Rochereau" (Paris 14). See maps on http://www.ratp.fr/plan-interactif/
Many offers for accomodation on the officila website "Paris Tourism Office"
http://en.parisinfo.com/where-to-sleep-in-paris