Isn't the actual distance to cover much shorter also at those latitudes, in order to 'circumnavigate' the globe? Because an equilatitude circle is much smaller.
Correct. Look at the specifics for Burt Rutan's Voyager world-record non-stop heavier-than-air circumnavigation. They specified the need to cross the equator twice in order to avoid such shenanigans, perhaps with a few more constraints.