What if there was fighting by both British and US ships during the Trent Affair?

May 2019
What if while arresting the two Confederate diplomats, some incident happened that led to fighting by both the British and US ships?

Or what if the two diplomats made it to the UK?

Would the Union still emerge victorious and reunite the country but with heavier loses?

Would the Union have lost the Southern States?

Would the Union have lost the Southern States and more territories?

Would the UK and France and other European nations gang up and destroy the US and recolonized some of its territories and give some back to the natives?