Noticed this discussion, so in case it was of interest to other viewers, I thought I would repost (with edits) a reply I made in the comments to someone asking about the history of these places (and the fact that the same names appeared in Who Rules the World).
YANGZHOU is supposedly roughly where modern day Jiangsu, Anhui, Shanghai, Zhejiang, Fujian, Jiangxi, provinces and parts of Hubei, Hunan and Guangdong are located, according to one historical text, but it seems like the credibility of all the existing historical texts are in dispute, so it's hard to pinpoint it's the exact geography. Modern day Yangzhou falls within these boundaries, but would fall in the northern part of the estimated region.
QINGZHOU is supposedly roughly where modern Shandong province is located
YOUZHOU at one point covered roughly Shanxi, Shandong, parts of Hebei, Liaoning, and Inner Mongolia provinces. As it shrank over time, it apparently became roughly where modern Beijing would be located.
So essentially, GJS and LYR travelled from the south to quite far north over the course of three months, including rest and recovery time. Given how far south Yangzhou may have stretched and how far north Youzhou stretched, their trek could have been twice as long. And assuming they fictionalized (or at least weren't being super precise) with the real-world geography/location, I'm guessing they were crossing the equivalent of the Gobi desert.
There are links to fuller articles about the historical places here: https://en.wikipedia.org/wiki/Twelve_Provinces
In both dramas, from what I can tell, they took names of real places in ancient China, but fictionalized the historical context (number of states ruled by the emperor/who ruled/how it was governed, etc.) Someone more familiar with the history and geography would probably have a better idea if they used similar geography or if they completely fictionalized the location as well. My sense is that they approximated the geography, but took some liberties as well in Destined. WRTW is highly fictionalized from what I can tell.
