It really depends on Tony I think. Dan could easily lose over 10 minutes to him in the TT's but Tony could lose a hell of a lot more in the mountains if he joins the bus to get over some of the tougher stages. That said if he's there or there abouts by the time they hit the hills he'll be obliged to try and not lose too much time.
I am sure if Tony is in the lead or a good position after the first TT, he won't just quit in the Gc. He'll certainly go full throttle in the stage to Toussouire then. Whatever happens there will decide his further tactics. If he loses time, he'll save energy and go for the last TT. If he limits his loses there, he'll try to hang on in the Pyrennes as long as he can.