I think Quintana can still win the Tour, but he needs to ride his own race. He doesn't need to attack now when Froome and Sky are strong - he has to ignore the idiotic fans and be patient. He needs to wait to the third week, when everyone is tired, and just ride the climbs at his threshold - if it's good enough to ride Froome off his wheel then so be it. Doing repeated attacks is such a counter-productive tactic for a rider with his power profile - especially when Sky still have numerous riders left in their train.