I was thinking more from the perspective of outsiders looking in. Tevinter will obviously have been watching with interest. They had already asked the Inquisition to deal with the Venatori cult on their borders (Nevarra claimed the same area so you had to acknowledge one request or the other - I chose Tevinter). Leaving aside Lelianna as she wouldn't be a contender on my two conscript playthroughs, I would have thought that Cassandra would be viewed by Tevinter as pretty much the same as before, even with reform. Vivienne on the other hand would be seen as a radical choice and her harsh but successful dealing with dissent would probably be approved of by the Magisters. Also if the Divine is meant to be the earthly icon of Andraste, then the Tevinter would feel that the south had finally acknowledged their interpretation of Andraste as a mage. She wouldn't necessarily have to interest herself at all in Tevinter politics for it to have an impact on thinking there. However, Vivienne does have correspondence with mages in Tevinter; she received a letter about Dorian. Given that even in Tevinter it is known that Dorian is the Inquisitor's paramour, it might even be assumed that Dorian had some part in getting a mage sat on the Sunburst Throne (even though he didn't) and that could improve his standing back home. After all it is widely acknowledged that Vivienne owes her success to the backing of the Inquisition (even if the Inquisitor himself doesn't actually remember doing so).
Have just been back and replayed the end after voting for Cassandra and she did get made Divine. So in this case at least it all depended on my vote. Now I have just have to decide which ending is better and the main difference does seem to be the mage Circle and how much unrest there is.