I have a friend who died and although he'd been estranged from his wife who lived in another country and they had no contact for several years she would still be his next of kin legally as his will was unsigned. Their are no contact details and she never sent the divorce papers back to him and seems to be uncontactable. How easy would it be for the family to get his estate transferred to his offspring if the estranged wife cannot be found?
Yes, getting married abroad can change a lot of things, especially if they lived in that country after the wedding. In France, for instance, children inherit not the spouse. This also applies for property bought in France unless legal forms are filled in.