Negrin, president of the Republic, followed the strategy of resisting until the start of the European conflict.
If Europe goes to war, before the civil war is over then France is almost certain to get involved, considering the military support that Franco got from the Axis and Britain will probably follow if only out of fear of Gibraltar being threatened.
A Nazi occupation of Spain is likely to be the short-term consequence with democracy or the monarchy being restored towards the end of WWII, although the sorry state of the country and the political class would make things mightily difficult.