It appears that no problem with the booking a hotel.
Sputnik Hotel (http://www.hotelsputnik.ru/numberse.htm)
Please note that all foreign citizens arriving to Russia have to fill in a migration card while passing through customs. The migration card is normally given before crossing the border (in airplanes, trains, buses, ships, etc.). Be careful in filling in this migration card and keep this card until leaving Russia.
Please, inform the local organizing committee your flight and arrival time.
As useful information, please, be aware of Aeroexpress trains link the airports with the city. You arrive, respectively, at the Kiyevsky, Paveletsky or Belorussky railway station. Then you will need to take either the Metro or a taxi from the station to the hotel (https://taxi.yandex.com/#index).