It comes across as a little dated. (When the hero sprays his pregnant wife's clothes with DDT because of flea concerns and it's considered a good thing, you gotta laugh.) But the core story holds up remarkably well. 
 Instead of the typical apocalyptic aftermath story with brave survivors fighting for survival, we get a small band of average people who would rather coast along by scrounging off the old world rather than trying to rebuild. 
 Stewart was doing a version of 'Life After People' decades before the new book and History channel series here with pretty detailed theories about the way things would break down. His view seems more optimistic than what would actually happen. (Electricity and running water lasting far longer than seems feasible.) But he obviously put a great deal of thought of how the break down of civilization would occur.