I've only been on Anna a couple times in the fall and only north of 208. How's late before the boat traffic dies down on a Saturday night to comfortably fish the main channel? Are the shoals well marked? Are there a lot of lights along shore? Houses, lighted docks, etc.
If it's not well lot and well marked I'll probably get a little more time on the lake before fishing it at night. I do plan to get there a few hours before dark to scout a bit and lay a GPS track.