There have been a few threads on this in the last two years. I’ve read through most of them before. Find the threads with Green Island or Orchid Island in the them, and wade through. I know there is discussion somewhere about CNY traffic.
In short, Green Island is incredibly busy, Orchid Island less so to reasonable. That is what I recall, but I haven’t been to either during CNY.
EDIT: Here are a couple of threads:
[The Islands Thread
[Taiwanese Islands (e.g., Green Island, Orchid Island, etc.)