It's more of a winter thing, usually (oddly enough), with people going out on a weekday night to classes and dances.

Mr Red is right about the large movements. Set dances - which are kind of like fast quadrilles - are designed so that large numbers of people can dance in a small area. In the old days you'd have two sets - 16 people - dancing in a kitchen, "around the floor and mind the dresser", while those resting sat around the edges cautiously consuming cups of tea and scones. So it should be easy to dance a set in a six-foot square.