Hmmmm... Corsica could have been maintained as an independent polity, but only if certain factors do come into play.
One can't eat marble. A Venice stuck on the Lagoon would be vulnerable to having it's supply of everything cut off.
Venice would still have some areas outside of its city probably and Venice could survive for centuries without the Terra Firma prior. With sufficient links and patrons (as Venice always had in its past) it can surely survive.
Regardless, my opinion would be that assuming Italy (as in the otl quasi nation state, not the long existing kingdom of Italy) is formed, the areas most likely to diverge would be:
"Survive" to the extent that a man in a terminal coma being strung up and jerked around like a puppet is technically "Alive". A Venice without the cloat to hold onto even it's historic mainland possessions is a regeime with no legitimacy or power in it's own right and will never be able to consistently win the war of culture required to keep the hearts and minds of it's people away from a succeeding Pan-Italian sentiment. Forget Venetian thriving as a language: it will be next to worthless for anybody in the middle or upper class or engaging deeply in the exterior trade which will be all the city has, and the money is likely to go into the hands of forgeiners. You'll need to import most of your specialist labor from your patrons: who'll prefer to do their thing in French or German or perhaps even Florintine Italian, and your homegrown cultural and literary output will be puny compared to the flood of Italian or Austrian competition.
A culture can maintain it's distinctness through isolation, strength, or sharp contrast with the competition. A tiny cosmopolitan Venice has none of these things and will drown
But Sardinia was part of the Kingdom of Sardinia, (Piedmont), and led the movement for Italian unification.Alongside Venice, Sardinia would be the other candidate.
But Sardinia was part of the Kingdom of Sardinia, (Piedmont), and led the movement for Italian unification.
This is true. Also, it could mean a Corsica not already ruled by France.That just means you need an 18th century POD, though this probably means Spanish, not independent, Sardinia.
It depends what type of Venice we are discussing, the Venice of 1200, without terra firma, yet holding its territories in the maritime sector or the Venice of 1700. In my opinion, a Venice that is able to say maintain itself without the Ottoman empire and instead rules varied holdings across the Adriatic, Aegean, Black Sea, Istria, Dalmatia, Albania, Cyprus, etc.. Would certainly have at least some ability to survive. Especially if with the maintenance of the empire extends to friendship with the Mamluk sultans and possibly control over Constantinople, what would develop in Venice is a large centre point for the trade from the east and migration to and fro from these places. Assuming there is at least some allies on the mainland, Venice can surely dissuade its enemies in Italy, especially if Venice can garner enough favor with the Papacy and the Empire, as Venice will in this tl, avoid its adventurism at land, for a more Mediterranean outlook.