My wife and I have gone through two instances of workshops being cancelled (after we had signed up). The first one was handled very well by the organizers. When signups did not come in at the expected rate, the organizers cancelled the workshop about two months prior to its scheduled start. This gave us plenty of time to rearrange our schedule and find another workshop that had openings.
This year we had a workshop cancelled 7 days prior to its scheduled start. The organizers said they were short of their breakeven point by two attendees. We were going to leave for the workshop a little early and travel in the area and afterwards continue on to another destination. I would hazard a guess that at least some others who signed up had similar plans. Newspaper deliveries cancelled, lawn care arranged, motel reservations made, etc., etc., etc. And of course at this late date there is no chance of getting into another workshop that would come anywhere near fitting in with the timeframe and planned travel area. So this summer there will be no workshop for us
. Needless to say, we will avoid anything to do with this organization from now on
In the future I will ask a workshop organizer to specify a go/no-go date for a workshop before signing up. If there isn't a reasonable amount of time between the go-date and the start of the workshop, we will pass on that workshop. Of course no one can guarantee that an instructor won't get sick, roads won't wash out, etc. However, when it comes to getting enough attendees, the workshop organizers need to have some respect for those attendees and set a date when they will commit to holding the workshop.
I'd be interested in hearing if others have had similar experiences and also what you feel would be a reasonable timeframe for the organizers to "bite the bullet" and make a decision whether or not to go ahead with the workshop based on the number of attendees signed up at that point.