They can bring to bear their contracting expertise to get medical facilities together quickly, likely temporary buildings and structures that can be thrown up quickly. I would say time is wasting — for the effort to begin. They need to be authorized now to do the work, identify an inventory of buildings that can be assembled and contractors who can do the work. Execute contracts for locations to be named later.
I think you will need to make educated guesses at locations for the facilities. Valuable time will be lost if you wait, to be sure. It is a classic military estimate and contingency planning effort — that must be done in concert with public health officials, Health and Human Services, and state and local public health agencies.