... might have added another page or two ...
No, this is not a "traveller-friendly" watch, or better: only a "eastward traveler-friendly" watch. As with 99% or all mechanical calendar watches, you can set the date forward only. The big date is not a UN (Oechslin) construction, but developed by Dubois-Dépraz. This means, it is not based on planetary (cycloidal) wheels, which can be moved forward and backward.
So if you are traveling backward over the data line, you have exactly these options you mentioned already: let the watch lie for a day, or adjust the calendar forward for a year. Thanks to the date quick-set, though, you won't need longer than two minutes for that.
Regards,
Marcus