You get what you ask for on this board, don't you? Is your reason for wanting to go as a duo based on not wanting the additional dynamics of a third? Personally, I would go with three, but that is because to me it mitigates the risk in a heavily crevassed area. Two people can normally travel faster and more efficiently than two, but on a 10 day trip, it may be more efficient to go with three. It really is up to your comfort level. I don't know what your level of cceptable risk is; but mine tells me to go with three. Best of luck, and I'd sure like to see a TR!