I am sharing an "office" with two desks and chairs and we have 23-inch monitors. Which is not great. I could get some screen goo reflective paint and paint a square on the wall and hang a projector pointing at that spot from across the room. With the reflective paint maybe it would work with the Sun leaking in. As long as beams of light don't interfere with each other as they cross (that's a joke physics fans), we could have a beam crossing the room the other way too.