Playing the Hedgehog is probably his best option, since it can be played against either 1. e4 or 1. d4. I normally don't like the idea of "holes" in the position, which is what happens when you flank a Bishop and play the pawn two file overs. You're supposed to play the pawn three files over. In other words, if the Bishop is at "g7", then you should play the d-pawn and not the e-pawn, and if the Bishop is at "b7", play the e-pawn and not the d-pawn. This will strengthen the holes at "c6", "f6", or "c3" and "f3" considerably.
However, in the Hedgehog, the Knight's play to "e7" and "d7" and so both center pawns can be moved. This gives White a nice space advantage though, and if judicious exchanges take place, Black is going to end up with holes in his position, which could be devastating in a Rook Ending.
The Hedgehog is difficult to beat down though, theory doesn't really favor it, Capablanca said it was lost (he disapproved of 1...g6 and 2...Bg7), and it takes a certain chess personality to really like so many pawns on the 3rd rank.
I do think it's much better than the "Tempo Down French/Bishop Locked Caro-Kann idea though, much better.
This is actually very close to what I shoot for... I find all that white can do is try squeezing me into a personal zugzwang, without any fruitful attacking chances, if I play well enough. Once I get any inaccuracy in play, to gain space, double a pawn, etc, I jump on it. I have actually used this position like a grinder and slowly worn several people to a nub. I enjoy it.
I play the Caro-Cann, and I actually think it can be a very interesting and agressive opening. Y'all should check out "Dangerous Weapons: The Caro-Kann" by IM John Emms and see what I'm talking about