Just to add a little, there are versions collected from England/Scotland/Ireland and Wales, as well as version from the US and Canada. The earliest printed copies in books seem to be in Scottish collections from the late 18C and early 19C. If you put Night Visiting Song or I Must Away Love in the Filter box with Age set to All you'll find several discussions of the song, as well as versions in the DT.

I give a version from Luke Kelly (1982 Dubliners, courtesy of YouTube) below; it looks like a fairly standard version that was being sung widely in UK folk clubs in the 60s and 70s.

Mick

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NIGHT VISITING SONG

I must away now, I can no longer tarry.
This morning's tempest I have to cross.
I must be guided without a stumble
Into the arms I love the most.

And when he came to his true love's dwelling
He knelt down gently upon a stone,
And through her window he's whispered lowly
"Is my true love within at home?".

Wake up, wake up, love, It is thine own true lover.
Wake up, wake up, love, and let me in;
For I am tired love and O so weary,
And more than near drenched to the skin

She's raised her up her down soft pillow
She's raisd her up and she's let him in,
And they were locked in each other's arms
Until that long night was past and gone.

And when the long night was past and over,
Ans when the small clouds began to grow,
He's taken her hand and they kissed and parted,
And he's saddled and mounted and away did go.

I must away now, I can no longer tarry.
This morning's tempest I have to cross
I must be guided without a stumble
Into the arms I love the most.

Source: The Dubliners: Luke Kelly vocal. Jan 1982