I normally close registration two weeks before the course start date.
This is done just so I can schedule the rest of my week.
If no one is registered for a course, then I know if I have enough time to go out of town, for example.
Now, it would be cool, if : Someone is registered for a course, the registration cut off date could be moved up. To say two days before the start date.
Here is an example:
Course is scheduled for August 30th. Normal cut-off would be August 16th (two weeks before) But on August 15th, a person registers for a course, now the cut-off date is moved to August 28th automatically. Since I have to be there anyway, lets have more of an opportunity for additional registrations.