presuming things are recognizably OTL (France invades Spain, US still having a conniption fit about Britain), I wonder how Britain would treat the war? in 1812, they're allied with Spain (any part of it that is battling Napoleon), and if their is still impressment crisis, the US may find itself fighting two countries. If the US cuts its teeth on Spain, when it takes on Britain, it's military could be ready, changing up the whole beginning of the British war - could we see US getting that golden chalice of mythological quests and taking Canada?
The whole thing is a mess: neither Spain, nor the US has much navy. Florida is the easiest target, and probably can be taken. Texas is ripe for the taking, as Mexico is in a state of rebellion and has its hands full in the main part of the colony (does this state of war put the rebellion on hold, or give it new life?), but as stated above, it is probably too far for the US to get to.
changing the state of Louisiana puts too many unknown variables into the equation. 10 years of continued ownership by Spain/France means 10 more years of growth and the territory is in a state of solid growth, especially New Orleans. We don't know who holds it, or how events have played out. Britain may have taken it from either France or Spain. The easiest assumption for any rational discussion is to leave it as OTL.