Programme for the Cardew events: http://www.cacbretigny.com/press/Cardew/GuideCardew.pdf
I am seriously tempted by this, but only if Lee is definitely taking part. I reckon I can get a ferry out from Portsmouth to Le Havre or Newhaven to Dieppe to arrive early on the Sunday morning, drive to Brétigny, see the show, drive back to Le Havre or Dieppe, catch a late ferry back on the Sunday evening, and be home in time for elevensies on the Monday morning. If Lee's not taking part, though, I'd sooner save myself for a proper Gate show.
Lee's in France now... There are SY shows in Europe late May, then no SY activity until late June... so Lee might be in Europe at the same time as Michael Morley is playing his shows... could they be doing more shows together than just this Cornelius Cardew thing?
(This is pure speculation/dreaming, I hasten to add)