Why not Emperor of New France
But in fact, Napoleon wanted to take a scientifical journey from North to south to study all the americas and write a book on his discoveries. Never forget that Napoleon was a scientist, a brilliant mathematician who was member of the Institut des Sciences in France. In real life, many bonapartist colonies were established in Louisiana...without the 100 days and the white terror to kill most of Republican and Bonapartists french, many thousands, even tens of thousands could emigrate in Louisiana.
And about the 400 hundred men...they are the Old Guard, la Vieille Garde, still recognised as the best soldiers to have ever existed. Don't underestimate them