The aired on November 25 because while mentioning the showcases, during an eBay postcard search, I found this entry mailed on December 12 and since Bill mentioned two more weeks, this looks to be a last-minute mailing entry. Of course, these special showcases returned during the '80s as the Home Viewer Showcases.
I couldn't imagine another such Around The World trip with over a dozen stops Sure, for a teacher its easy to take during a summer, but I couldn't imagine more than a three-week trip based on those shown during the CBS era (and quite frankly aren't as common as they once were with the FRATS being the replacement since three-week vacations are unsuitable for many more people nowadays). Unfortunately, it doesn't mention the total length of the journey, though I'd imagine it would probably be at least 25 days with all those stops, and if such a trip were offered today with first-class, it would easily top $100,000.
Also, based on these findings, this would be the first primetime episode that aired following my father's birthday four days after this.