At least at the southern edge of the little Karoo around Prince Albert, they were up and active in early October, recall south of the equator so that would be like early April here.
Maybe some of your RSA folks could chime in on when they seem to 'go missing' for awhile. Is that weather related??
One of my fellow crew members over there lived in a mountainous region of SA and he said they get snow sometimes. He said the leopards there all hibernated in winter.