I seem to have found a potential solution to prevent a TextView in GridLayout from growing unboundedly and pushing out other views. Not sure if this has been documented before.
You need to use fill layout_gravity and set an arbitrary layout_width or width on the long TextView in need of ellipsizing.
android:layout_gravity="fill"
android:layout_width="1dp"
Works for both GridLayout and android.support.v7.widget.GridLayout