In all probability, the delegates would have been arrested in case British authorities could lay a finger on them. However, after a few years, once the animosity of the failed revolution had waned, the delegates would have been offered a political pardon, on the condition they would never again incite others to take the arms against the Motherland, Britain.
The British would have not had the delegates executed because that action might have reignited the rage of the American colonists.
