Ahhh, but you are speaking of the ILC, a superconducting juggernaut of some 50km which can still only reach the puny collision energy of 0.5TeV. Why go for such a thing when the much more attractive possibility of CLIC exist? A delicious 3TeV of electron-positron collisions at ultra high luminocity. No troublesome and gradient limiting superconductive cavities either. With 100MV/m we are far above the theoretical limitations of the enemy competition. First beam? Around 2023, optimistically.

(Me? Biased? Naaahhh...)