Between 6" and 7" of ice is what I ran into on Lambach lake just above Lake of the Hills on the side next to 280. Me and the kids got 7 blue gills and about 4 bass in about 12' - 15' depth on Sunday around noon.
Regarding the SE section of the boat ramp on Lake of the Hills, last year I noticed that the last part to freeze up was this area. If you head straight east from the start of the rocky pier (where it meets the shore), once you get to the curve of the shore that heads out to boat ramp, that area must have some warmer water flow that makes that section freeze last. When I found 8-10" in other areas on the lake, that area was around 6".