Sorry, no Lake Trout in Christmas Lake. Their might be a few Rainbow Trout left over from the 2016 stocking, but they discontinued stocking in 2016, and trout will be few and far between. The closest lake to the Twin Cities with Lake Trout is Grindstone Lake, up past Hinckley. Trout season opens up January 12th this year.
Definitely no lake trout in the cities. But there are a couple rainbow stocked lakes. Dnr website will show the stocked lakes. Courthouse in chan or chaska comes to mind. I’ve never fished it, but from the pictures I’ve seen it is literally a zoo on opener.