You don't need to wonder. Look to Japan for the broad strokes: property in cities will still have value while rural areas fall into decay.
In more words: young people will crowd into cities in order to meet other young people and find work, while aged areas descend into irrelevance and whatever this is: [1]
Due to this, Greater Tokyo now contains 1/3rd the population of Japan[2]. While you can find a number of articles claiming it's cheap compared to metros in other countries, or horrifically expensive[3][4], whichever it may be it is certainly better than what's in [1].
