In one village the English speaker was an American oil drilling engineer who changed course to become a philosophy professor, and then changed course again to live out his retirement in this tiny Greek mountain town. I really regret not staying longer there.
In the next town, the English speaker was a guy who had left 30 years ago to work in the Canadian fishing industry, and only returned a week previously. He translated for a lot of the family elders, who were reaaally old and remembered doing the yearly pilgrimage on foot through the mountain passes.
(Then I came to a town and chatted with a random person... When I described where I had been and where I was going, she crossed herself and begged me to turn back! Felt like a scene from a Dracula knock off...)
And finally, I came to a very remote village, where I was housed by an Canadian woman who had lived in the village for like sixty years and forgotten all of her English! (Which was communicated through a combination of artifacts, drawing, and pantomime.)
Which is to say, you've gotta get real far off the beaten path to find places where no one speaks English. And even then, people are helpful and fascinating.
I've traveled with people who are (forgive me for the bad wording) equally as easily confused as your wife, if not worse, and into the middle of jungles and villages of far off places. In the 19th century this would've been extremely difficult and dangerous. In the 21st century, you're honestly probably safer wandering around cluelessly in more of the world than you are in the US.
And I never felt like I was missing out by not being able to read a random thing in a language I don't know. Tourist locations, especially places like museums and historical sites, will almost always have full English translations of whatever the local language is.
There's no "winging" it. You can plan for a country even when you don't know the language. Just save locations on google maps and go.