Let's say that a series of multiple fortunate events mean that today we still have the Russian Empire of the Romanovs existing through reforms, avoiding a bloody revolution and even being part of the European Union, with this we would reach the End of WW1 where Russia finally I would get Constantinople and an exit to the Mediterranean Sea, but returning to the central issue, how could the life of Tsargrad (Constantinople/Istanbul) develop as a Russian enclave in Anatolia? What kind of trouble could it experience over 104 years as a Russian governorate apart from the Turkish War of Independence? What effects would the possession of Tsargrad have for Russia? What difficulties could it mean for Turkiye to have Eastern Thrace separated from the rest of the territory (assuming it remains Turkish in some way)?