That 12" screen is actually 245 DPI. As someone growing up in the 21st century, I'd consider 96 DPI as the standard, so probably a 2.5x or 3x scale would be much better, since I suspect your age would make you sit further from the screen.
I'm using awesome too and I also don't think it's easy to have HiDPI set up on X11. The good thing about awesome is that you can crank up all of the widgets, but e.g. GTK+ and Qt are more difficult to get to look nice.
My personal suggestion for you though, @florian, is to buy a big screen with normal DPI to use at home. I'm in my early 20s and I can't even stand my 144 DPI laptop screen for a long period of time—my new 1920x1080 23" external monitor is a life-saver: I can even crank the terminal font size up to 15 and lived a blessed life ever since.