That is possible isn't it? I know I have the port for it but I'm not sure if I can use it as a second screeen.
Most of the time, laptops are able to clone views bot not utilise their screen as a span over the additional port. The only way to check this is to try it of course, but alternatively, you do not need all 5 screens up at once. If you keep your main screen as a maximised view, and the other four using maximiser to take up 1/4 of the screen each (in case you need to view with them) but behind the main view, you should be fine as long as you have good mods set up through the main screen. I would avoid collection quests in this manner, or you will spend a lot of time minimising and restoring the main screen.