If he intervenes late in the game, he'll have a hard time being critical of your efforts, seeing as how you're following the consulting recommendations and have kept him in the loop every step of the way. If he tells you to pull the plug or change direction in a significant way, agree, and let him know you'll inform everyone of his decision.
Here's what's likely, if my inferences regarding the situation are on target: The CIO is in the process of committing career suicide. Your path to success is to outlast him without acquiring the taint of being part of his inner circle and without acquiring any stigma of being either ineffective or insubordinate.
Nothing is certain in a situation like this. The steps I've outlined should give you a pretty good shot at navigating through it.
This story, "Can't get hold of your boss? Take advantage of the situation," was originally published at InfoWorld.com.