The only other option is to use the viewfinder but for me this means holding the camera right up to my face, giving me less control over the buttons and dials. It's also a smaller screen to be looking at, which over the course of a few hours can give you a headache.
So I got to work trying to resolve this with a cheap viewfinder loupe that I'd bought a few years ago for my Nikon D7000.
By flipping the viewfinder upside down and screwing a hole through the bottom, I was able to attach it to the back end of my Manfrotto BeFree Live tripod mount.
I could then attach the tripod mount as normal to the bottom of the Sony. And voila! It's not perfect but it's pretty solid and now makes shooting and reviewing both photos and videos outdoors actually possible!