The EDTs of all of the Chanel exclusives vary in longevity. The best seems to be Coromandel and the Chanel Cuir de Russie.
I have both the EDT and parfum of Bois des Iles, and I layer them over an unscented silicone-based skin lotion. (Try Aveeno unscented lotion.) You can also purchase Chanel's Fresh Body Creme (pricey) skin creme made to layer to see if they have any more longevity. This cream does have a slight scent that alters the scent you layer it with.
As with almost all scents, the amount of alcohol gives great sillage but lowers longevity. The parfums last well but stay much closer to the skin.
You may have to experiment or use both.