I definitely think this song is about a death rather than the end of a relationship, the line about the phone ringing early seems to be more fitting with this idea.
I always interpreted it as the death of someone who he was having an affair with,
"with someone new I could have started" is refering to how he could have left his wife to be with this person. The lines about arguing with his wife seem to fit in with the idea that he wasn't happily married.
"You're smaller than my wife imagined
surprised you were human" for some reason the surprised you were human part always suggests to me the idea of an affair.
I definitely think this song is about a death rather than the end of a relationship, the line about the phone ringing early seems to be more fitting with this idea. I always interpreted it as the death of someone who he was having an affair with, "with someone new I could have started" is refering to how he could have left his wife to be with this person. The lines about arguing with his wife seem to fit in with the idea that he wasn't happily married. "You're smaller than my wife imagined surprised you were human" for some reason the surprised you were human part always suggests to me the idea of an affair.