depends...
If your spouse leaves you and commits adultery its best to seek a new spouse. Man (and Woman) should not be alone. If the spouse who leaves is unsaved and shows no signs of beginning regeneration then the one who was left can and should move one.
But if your spouse who left is (1) not in a sexual relationship with another and is either a christian or moving that way reconciliation should be sought.
Be the stoic myrter while ones spouse has moved on with their life only causes pain and is not God glorifying.
It is not God-glorifying to go against your vow, which was “until [only) death do us part.”
If you don’t vow that, then I might buy the rest of your argument. With a vow to God, only you can break it, regardless of what another does.
Christians should not be marrying someone who is not a Christian, anyway. You must be “equally yoked.”
Christians are free to marry another when their spouse or former spouse dies.
Horse apples. Single works best for me.
/johnny