I have been lurking in the background for a couple weeks reading most of the postings for over 50 and commuting. I have enjoyed "listening" to the comments and have even applied some to my daily commute.
Of course my commute is only 15 miles round trip. It is thoroughly enjoyable and I add to it each afternoon to get to ~20 miles for the day.
My beloved 2001 Litespeed Tuscany and my 2014 Cannondale SuperSix EVO Hi-Mod Team bike
I'm 60 and my commute is only 17 miles round trip, and like you I'm always looking for a few extra "enjoyable" miles. Hard to find "enjoyable" in many parts of Atlanta.
When the spirits are low, when the day appears dark, when work becomes monotonous, when hope hardly seems worth having, just mount a bicycle and go out for a spin down the road, without thought on anything but the ride you are taking. — Arthur Conan Doyle