I have no plans for streaming my solo games, but I have a couple of ideas if I were. Nothing revolutionary, just a couple of thoughts in my head that I need to share.
If I were going to use an overhead camera mount, I'd definitely try to use a battle mat with some features. Loke BattleMats has several books with premade dungeons and wilderness settings (Note that I am not endorsing Loke or any other product; I just need a convenient example). I would use 2D tokens in place of miniatures; they'd be easier for the audience to discern. I would have the camera angle wide enough to see my dice rolls, ideally on a dice tray.
If I were going to use a regular tripod instead, I'd hang a magnetic whiteboard with grids on a wall. I would have to draw the terrain. I would still use tokens, but they would be glued to magnetic bases. The audience wouldn't be able to see the dice rolls, so I'd have to announce the results. This way is less visually appealing, but it may be simpler and possibly cheaper.