Marni, a long time ago I posted a formula that my engineer husband Chris gave me that explains why you suffer more from a headwind than you benefit from turning around and using it as a tailwind. It was a comforting and amusing way to quantify headwind suffering. I will try to dig it up for you. And 20 miles of headwinds IS a long ride.
Chris actually came out to Texas last May and did this ride: https://sites.google.com/site/texasstampede1200/. And, he said, out of the three and a half days, about three were headwind days. I believe I remember hearing the phrase "soul-sucking headwinds". But he had a great time and really likes the Texas randos.
Put your feet up and know you had a hard-workin' day.