One must use a kli (cup) that holds a reviit of water, however I am curious if the kli must hold a reviit all in 1 location or can the water be spread out over multiple locations if it is connected (i.e. can one use an ice tray for netillat yadaiim)?

Indeed the reviit should be in one receptacle. It would seem to me, that if we are referring to a plastic ice tray in which the water is held in separate cubicles, it would be no different than doing netilat yadaim with 12 individual whisky cups, which would not be a proper netilat yadaim since there is no reviit in a single cup.