I try to avoid long stretches of some of these narrow roads every chance I get. It's inevitable that you're going to get close calls sometimes when you have both oncoming and passing traffic. There's a narrow road on my way to my local mup but it's not heavily trafficked or very long for my part. And there's not an alternate route that isn't worse. I don't think I'd sweat the under 3 feet thing in those circumstances unless it was really close enough to risk contact.

The only time I've lost my cool with a motorist was on a pretty wide stretch of city street with no oncoming traffic when the driver both buzzed me and yelled at me (I was within 2 feet of the edge). That's all he was willing to do. That was almost 20 years ago.