This may be more challenging than you think; depending on how you 'fold' the sails, you may end up with enough 'windage' 'aloft' to over-stress the connections

This may be more challenging than you think; depending on how you 'fold' the sails, you may end up with enough 'windage' 'aloft' to over-stress the connections anyway. They'll likely be forced to bring the wing down completely, which will either make the wings small or expensive.