I think things would go pretty much as in our timeline. The War of the First Coalition was already ongoing to contain if not overthrow revolutionary France by the middle of 1792 before Louis and family made their break for freedom, all that would really change I think would be that he'd have to make a quick exit from Austria to somewhere neutral out of their reach like Britain if the Coalition lost and there was a Treaty of Campo Formio. Things settle down to a hostile peace and then cue the War of the Second Coalition when they decide to have another go, and the Napoleonic Wars carry on from there.