The potential loss of the West Antarctic ice sheet is the major uncertainty associated with projections of future sea-level rise. The ice sheet is thought to be susceptible to the Marine Ice-Sheet Instability. The extent to which it is genuinely unstable, in the sense that a collapse, once triggered, becomes irreversible and independent of changes in forcing (in this case ocean temperatures) has yet to be determined. The magnitude of oceanic warming required to trigger any such instability is also poorly constrained. Here we use the adaptive-mesh BISICLES model in an ensemble of experiments to investigate the potential for quasi-stable states and regrowth of the ice sheet. The work has implications for both committed future sea level rise under various emission scenarios, as well as understanding the contribution of the ice sheet to higher sea levels during the Last Interglacial.