We went in early November and there seemed to be plenty of activities posted. We only went to ones in the evening, though if we go again, I would like to try some during the day as well. The campfire, sing-along, and movie happened every night we were there.
It was not too hot then, though at night it was downright chilly. I would go again at the same time of year, but would make sure the heater was working before I left home.
Also, the parks are not too crowded then, esp. after Jersey Week.