I have to agree with Howard on this.
In the days when most people were using CRT monitors in their cabs, you couldn't really go much above 20 inches or so as, beyond that size, CRT monitors (and TVs) need a lot of space behind the display, and are extremely heavy. So, it made sense to maximise the usable display area for both vertical and horizontal games by allowing the display to rotate.
However, with flat screen displays, there is no practical limit to how big they can be. I've seen 43 inch 4K monitors being advertised recently for very reasonable prices. So, why not just buy a bigger monitor? Or, if that's not possible, have you considered using a fresnel lens to magnify the display?