So, on the last day when the £1M is needed, what happens if the figure is only, let's say for argument sake, £750,000. Two questions arise. Is this the end of the Vulcan? and if so, what happens to that £750,000, does it get returned to those who have donated?
No money would ever be returned simply because it has never been taken in the first place.
That's the nature of the pledge scheme. The money isn't called upon unless the target is reached.