How long does it take to learn the average new country song on acoustic guitar?

That really depends on the skill level of the person playing the guitar.

Could be as short as 20 minutes or as long as a couple hours.

I played guitar many years ago.  I haven't picked up my guitar in over 20 years.  But when I did play, I could learn and play most country music in about 30 minutes.

Six point two.

That would depend on the ability of the person doing the learning and the difficulty of the song.

For someone that's a reasonable player learning to accompany a song that uses the chords C Am F and G wouldn't require much “learning” at all. A beginner trying to learn something really complex might never manage it.

It takes about 25 minutes from beginning to end. Country music is very simple and doesn't vary much. It is basically the same music and lyrics.