How do I get a good estimate on the number of hotel rooms I need to reserve? Most people will not be out-of-town guests but I don't want to block off way more than what's needed (don't they charge you for reserved rooms not used?). Also, should I pay for the rooms for my out-of-town ceremony participants, like the uncle from 2 hrs away who'll be officiating? I don't mind doing so, I'm just not sure what that tradition is.