[@Willy Vereb]

And even lacking the Austrian app, checking back at what I had written for the OP clarifies the situation in Italy:

[quote] Italy appears as ever before but as French and Austrian troops occupy the streets.[/quote]

So on those grounds I would have to reject a surviving Napoleonic republic at Venice.

The point of divergence is also more or less the Treaty of Tilsit, where Napoleon decided to instead just go ahead and go gamer on the Prussians as a flex and turned around on the Russians when they protested to re-discipline them back into the Continental System, for a time