Genie I too love this old song even though it does extol the pleasure of alcohol. I have attempted a translation keeping as close to the original text meaning and meter as possible. I have added a phrase and a few words just to make up that meter.
See if you like it and perhaps you can learn it quickly enough to sing on "The Night" ?

1
The two Johns and this John, went over to the fair,
they started up a row there that was difficult to repair,
They broke each other's heads and the woman of the Tavern
was the one who minded my bald pate as shiny as a sovereign.
And I'll find my little jug again and that 'll be grand.

Cho.
I'll take my little jug again,
Here's health my little love again,
It minds me not though her sweet head
be fair or dark or curled,
I will take again my little jug and that 'll be grand.

2.
My wife I sent to Cashel, selling apples there you see,
Two sales of half a penny was all she brought back to me,
Aren't I a pity to Mary now, walking the country oér,
Searching for that same ould flirt for whom her home's too poor
But, I'll take my little jug again and that'll be grand.

3.
My blessings now I'm leaving to the people of this house,
For here they be both young and old, (with them I have no grouse)
And never will I tire of them and their company so jolly
'Till through the roof of this old place will grow a bush of holly.
And I'll take my little jug again and that 'll be grand.

SING OUT
And the blessings of St.Patrick be with you :)