I do have a desktop resolution of 3840x2160 and a scaling of 175%. KotC2 is running, but the window is quite small. If I change to fullscreen, the size of the game itself is not changed, there are only additional black areas.
I am now using a tiny program, that resizes the window to a proper size: http://www.brianapps.net/sizer4/, so the game is playable.
I would prefer a native possibility to play the game, though.