That's assuming that an independent Buenos Aires (ca. 1810-1840s) that at least officially is - in a number of ways and much of the time - on the side of the British still attempts to assert control over all the rest of the OTL United Provinces of La Plata. But Cordoba may very well hate both Buenos Aires and the British - after all, in 1806, it was to Cordoba that the Marquis de Sobremonte fled in the wake of the first British invasion of Buenos Aires in 1806. Thus, Cordoba may well want to become independent of both the British and the newly-independent Buenos Aires (perhaps temporarily being a Spanish Royalist stronghold until the independence-movement convulsions of 1810s Spanish America). After its own independence, Cordoba may control a whole country spanning the entire interior, up to around Salta, or it might break up into some smaller republics - Cordoba, Cuyo (Mendoza/San Juan and maybe San Luis and/or La Rioja), Tucuman (plus Catamarca, Santiago del Estero, and maybe La Rioja), and Salta (plus Jujuy and Nueva Oran). If the latter possibility, Cuyo might well possibly unite with Chile and Salta etc. with Bolivia. I definitely see those areas, and those further south, as belonging to the British - and not to Chile - once the Mapuche and so forth are subdued. Britain did have the Maitland Plan, created by Major General Thomas Maitland in 1800 in order for Great Britain to compensate for the loss of most of its North American colonies during the American Revolution. While it was never employed by Britain, Home Riggs Popham (the instigator of the ad hoc 1806 invasion of Buenos Aires) did use it. Even though Popham didn't have official permission, he felt that his actions were based at least loosely on general, vague British plans/proposals. [Edit] Moreover, the British invested much effort, energy, and resources in India from the time that they (and other European colonial powers) established some trading posts there. In that sense, the British in South America were kind of like the British in India minus the formal colonies. With a successful conquest of Buenos Aires, the two situations would have been somewhat more similar than IOTL. Again, as I mentioned earlier, the Spanish would have been too weak to demand the British to give back newly-captured lands, especially after the invasion of Spain by Joseph Bonaparte in 1807-08. Plus, there should be enough British forces, plus Portuguese and indigenous allies, to not be kicked out of South America altogether by rebellious locals.