The phrase "ambitious vision" means having a great and bold idea or goal for the future that requires a lot of effort, drive, and determination to achieve. Full definition
Students make dramatic academic progress when, from the very beginning, teachers develop a clear, ambitious vision of success. (teachingasleadership.org)
But the researcher has an even more ambitious vision. (sciencedaily.com)
Of course, we know a massive, crazy ambitious vision is critical to venture startups. (inc.com)