the music, the location, whether we are vendors, the audience.

If we don't like the music, we don't go, no matter how close it is.
In the US, within a full day's drive to go semiregularly, like Champlain Valley in northern Vermont. But we could go once to a distant festival that sounds particularly promising. We do go to the UK for Whitby and try one other festival near Whitby in time and place. We don't take CAMSCO more than several hours drive away. One of the festivals we go to at least as much for seeing old friends in the audience as for the music.