As an touristic hotspot, Delft has a variety of hotels. If you think of booking a hotel in Delft then it is adviced to book as early as possible.
The Hague (in Dutch: Den Haag) and Rotterdam are the two larger cities which are very near to Delft with excellent train connections (The Hague Central to Delft Central: 12 minutes (€ 2.50) and Rotterdam Central to Delft Central 12 minutes (€ 3.40)). Therefore it might be interesting to consider to book your hotel in The Government City (Den Haag) or in the Modern Archicture City (Rotterdam).
The ReMAR organization has not made any arrangements with hotels.