I agree, it's tough. Not much to do really, but if I would do this, I'd stay away from changing the methodology and the code, and make it clear that it will be

I agree, it's tough. Not much to do really, but if I would do this, I'd stay away from changing the methodology and the code, and make it clear that it will be tough to make this fly. Focus on: Reduce scope. Make sure only the important features are built. Set up periodic meetings with all stakeholders to prioritize (down) features and subfeatures. Get a grip on what's built and what's left. Make a realistic prognosis and make sure to anchor the new realistic target date with the stakeholders. Make sure bugs and tasks are tracked. Set up manual testing routines with some experienced testers. A big team if the automatic tests are of low quality. Iterate and prioritize this list constantly.