Umm, I'm amused on this one. I like to sing this song and sing it in a light-hearted fashion. It never occured to me to think of it as having any particular Pagan significance. The words I sing in the last verse are;

So maids let us drink down the sun,
And maids let us drink down the moon,
Take your man into the wood
If you really think you should
He might catch you a small bird or two.

I always thought drinking down the sun and drinking down the moon meant that you drank through sunset and moonset, i.e. for a long night of merry-making. I did change the words slightly from what I had read by replacing "lads"with "maid".