Why not in Exeter instead? It could be a good spot for a test run. This blog is mostly about canals but there is also in Exeter a flood prevention scheme that allows plenty of space. Other spots are available, similar to the Hackney Marshes in some ways. Photos show how it might look.
Even more likley would be a visit to Mama Stones by Raphael Saadiq. He could be a support act of sorts but may appear as the final act if Mick Jagger needs a rest towards the end of the evening. At a previous event near Exeter Van Morrison chose the afternoon and Nina Simone was followed by the London Community Gospel Choir with endless energy.
