If Voldemort had planned to kill Lily, would her sacrifice have saved Harry?

In Deathly Hallows, we find out Voldemort never intended killing Lily, upon entering Godric's Hollow, if she hadn't put herself in the way of Harry.

Had he specifically intended to kill all three inhabitants, would her act of sacrifice have been powerful enough to save Harry's life? If the decision hadn't actually changed her own fate.