Does a divorce take effect if the wife leaves the house she is living in—by government order—to another house, after her husband swore: "Divorce be upon me if I leave this house except to this (new) house or a house of my own"?

Your husband will not be in violation of his oath by moving in this situation, because he is compelled to do so, and one who is compelled is not considered to have violated an oath, according to the most authoritative opinions of the scholars.