A couple of other possibilities, overlapping with what other people have mentoned:

Beer festivals/promotions:
The Topic in Bradford did a one-off one-day Saturday event alongside a beer promotion by its host pub, the Cock and Bottle.

Some villages - Wedmore, for example - have weekend-long real ale festivals and associated music, which might as well be folk as jazz or rock or anything else.

Theatre:
Barry Smith (barrysmithmusic.co.uk/) for one has combined youth theatre and folk; and in my area a year ago there was some kind of locally-touring local-interest amateur-run play that also incorporated folk musicians (David and Issy Emeny I think) but I didn't see it and have lost the bumf.