Unless (and this is a pretty big unless) Sky know something we don't about one of the climbs where they are confident that Brad can climb it at a far higher watts per kg than we have previously seen thereby putting a minute or more in Nibbles then I would say that that no dilemma exists.
I saw an interesting chat with Dave Brailsford after the stage yesterday where he said that they have to attack wherever they can. He wasn't playing down what Brad may or may not do.
I think that Uran is now plan A but I can't see him winning the whole thing.