Many of my friends traveled to Russia, but from Serbia, so I can't help you a lot. The only thing I know is that they were traveling from Moscow to Petersburg by a train and it was a night trip that lasts about 8 hours (it's the best option because you get there in the morning). I don't know how long it takes to get to Moscow from Paris by a train (it takes 48 hours from Serbia
), but I'm sure it's a better option to travel by a plane. It's simply better to get there fresh and ready for sightseeing than to come tired and waste the time sleeping. As we all know, Russia is beautiful and huge, everybody says that even one month is not enough to see half of the things you want to see. None of my friends stayed in a hotel, so unfortunately, I can't help you there neither, but I can get all the kinds of other infos if you need it. One of my friends goes to Russia at least twice a year, so I can ask him about some details, if you're interested.