Personally, I would not go to hear a band perform unless they included a substantial percentage of songs, no matter how good they were. Just personal taste this, but most people who go to folk clubs like to join in on the choruses or sing along.

Music-only bands are OK for dances, because there would be something else to do other than just listen.

You are likely to find bookings restricted to dances unless you include at least a goodly proportion of songs.

The folk clubs I go to would rarely (if ever) book bands who did not also sing.

Good luck, whatever you decide to do.