We're facing a variant of this problem right now. I just found out that the
Nelson dance needs to be canceled this coming Monday because of the
presidential primary election (we dance in our Town Hall). We've had
trouble with the election setup in the past, and knew that we'd have to
cancel the dance in November, but had assumed (always dangerous) that next
week's primary could co-exist with the dance.
So that's another form of "when to cancel the dance."
Lisa
Nelson, NH