If you have small hands you have the alt and ctrl keys. If you have big hands you have the function keys.
You also have a hidden bar behind your main bar that shares your main bars keybinds. Making a small macro to switch to that bar isn't difficult.
Heck, if I'm not mistaken you can do that with any hidden bar and any displayed bar. The macro takes up a slot on each bar, but instead of having 12 active keybinds for spells you now have 22 on one bar with only 11 keybinds.
Do that with your shift hot bar as well and you now have 44 open slots on 22 keybinds.
This is what I do. I have a bar set up with normal keybinds that feel good for me to use. I then have a second hidden bar behind it that I switch to using Caps Lock. (Mind you, I had to macro my keyboard to change caps to one of my NumLock keys because the game doesn't allow you to bind to Caps for some reason.)
And then I have a third hot bar next to my main one with all of my primary keybinds with shift modifiers.
And then a fourth bar with misc keybinds that aren't used every minute.
I have 34 active slots on 23 keybinds. (Half of which are just shift modifiers.) Plus a few misc keybinds on top of that.
It's not all that hard to find room if you get creative.