At this point is there even a significant colony left?
To my knowledge OTL 1860s European control in the hemisphere is limited to the carribean, Guiana, and a few british holdings like belize or the falklands. The british stuff is a non-issue now, and the carribean is being completely turned over to our new allies.
Compared to the valuable (if slowly getting less valuable) carribean plantations, Guiana is so much of a rump at this point I don't think we can expect significant European meddling in the hemisphere. It was always a sparse, low density area. Victory here pretty much eliminates any concern about Europe coming over to bother the Americas any time soon. I can accept a tiny spit of land that no European is ever going to be able to use for much of anything, because this war is like the Louisiana Purchase. Its a final nail in the coffin, plain to see for any colonial power, that the Americas are practically out of reach.
We need time to regroup, to establish reconstruction, build our economy, keep our base happy and solidify our new allies. Give it a decade, and we can come back for round 2. Maybe mop up the rest of Spain's crumbling empire, or intervene in britain.