You need to consult a lawyer on this as it can get a bit weedy.Thanks for constructing this hypothetical. I don't desire permanent residence status now, much less when my Arg mate dies. (If I did, there's probably a method for a financially well situated retiree to qualify.) I have no assets in Arg and I have a will that disposes of all my personal and real property in the US.
However, you do raise an interesting issue. Should my wife predecease me, we would want her real property in Arg to go to her daughter. Does a surviving spouse have an absolute, non-extinguishable right to share in the real property held in the sole name of the deceased spouse? Can the surviving husband's right to share in the deceased wife's real property be terminated by testamentary disposition, i.e. by a will?
Generally speaking, only a certain % of the estate can be given away by will (it used to be a fifth I think, could be more now).
The rest goes to the surviving spouse and children automatically (there may be an exception if a party renounces their claim/right). (Also , the % attributed to each party is based on whether the assets in question were 'ganancial' or 'propio').
Don't quote me on all of this as it's a messy legal framework and changes all the time.
This should give you a rough idea/starting point for research however. Make sure to check all the details. And when in doubt, ask a lawyer (though not one from this forum imho)
You can also read a bit more on Google of course; I did a quick search and found a few links, this one seems ok , though I'm not totally sure that it's up to date.