What Cruz wants is to be no lower than 2nd place. With Trump’s negatives so low right now, we will have no idea of his true national strength for awhile. If his negatives begin to drop —I think these are false indicators—then both Kasich and Cruz may make difference decisions about the value of the VP. If either guesses Trump will lose, then they will start looking to 2020. Kasich is now very strong in OHIO. He can afford to wait to.
Cruz will not be the VP choice. VPs are chosen to enhance general election chances, and that is not something Ted can provide.