That would definitely be tough but I wouldn't have to finish my studies in 2 years. I may extend it for a year. I think receiving ESOP is amazing and it implies that you should direct all you forces for studying and research and finish your studies in 2 years. fixed. If you don't get it I don't think you have to do that. You will get connections, work on amazing projects it would open so many doors. After all getting degree from ETH is itself an achievement. Speaking for myself I think grades are not as important as research and practical experience.