"just a quick breath after each line of verse"
We have singing exercises for breathing that can extend it beyond that
One of MacColl's Party pieces was to sing a verse of Galway Races in one breath - Tail Toddle he could manage at his best - - 2 choruses and a verse in one breath (I have recordings of him doing it somewhere)
I managed 'Galway' a few times when I was young and Tail Toddle twice
These were exercises - not for public performances
The trick with singing is to be able to manage a snatch break at a comma and a full breath at a full stop - as you would if you were speaking it
(Jim)...In my song about (just!) swimming from "State to State" in Australia, I use both one breath per line of verse, and one breath per stanza for affect; but, generally, I think one breath per line is good as it marks where each line of verse begins and ends - rather than put the words on a screen, as happens at some churches.

When I am reading poetry aloud I do the same - one breath per line of verse so folks know where I am at.

On my tenor records, I occasionally practise C - g and back again, chromatically, on one breath.