I do wish that people would not refer to the Folk Week and Regatta clashing.
It is not true - the Regatta, for reasons I have never been able to fathom, decide to share their dates with Folk Week on an arbitrary basis. They say it is to do with the tides but that has been proved a nonsense on more than one occasion. I suspect the real reason is that they wish to have the event as late in the year as possible as it marks the end of their season.
In planning Folk Weeks during my tenancy I always planned for a joint weekend - whether or not it was happening.   
The comments above regarding the coincidence of dates emanate from my alerting Folk Week participants and Mudcatters to the position for 2021.