I went to the Slough on Sat. the 28th and there was a solid 6" of ice when we got the lake in the AM. It got pretty soft on our way off the ice since the weather was around 45 degrees or so and sunny. I would imagine that everything would have frozen back solid since this cold weather hit. There should be at least 6", if not more so you should be safe. I plan on going there New Years Day.
Also, we caught about 7 bass on tip ups using medium sized fat heads. No gills, but I did talk to a few guys who were catchin some decent ones that day. Later!