ὁ λαγὼς τὸν περὶ τῶν κρεῶν δρόμον τρέχει → save one's bacon, save one's neck, save one's skin
except: P. and V. πλήν.
failing this: P. and V. εἰ δὲ μή.
Best of all, let us make terms for ever. Failing that…: P. μάλιστα μὲν εἰς ἀΐδιον συμβῶμεν, εἰ δὲ μὴ… (Thuc. 4, 63).