Based on the reporting, roadway maps, and my knowledge of the Houston area (including having been there during previous flood events), for the area roughly bounded by the Outer Loop (TX-8) I'd say SW (towards and including Sugarland), SE (towards Hobby and Galveston), and NW (particularly Greenspoint, which is a frequent flooder) are the most likely 'zones' to have hotels that were affected.

Properties close to the IAH airport are probably heavily booked, if not at full capacity, somewhat related to UA's IRROPS at its large hub.