I think much of the work being done by what you think of as frugality here is actually being done by slack: creating conditions under which you have enough flexibility to take advantage of situations when they arise and not be so attached to things as they are that you miss opportunities you value after taking. Only in your first case do I think frugality does the heavy lifting; everywhere else it is a way you created slack for yourself, but it could have been accomplished many other ways while living a more materially lavish life.
I think much of the work being done by what you think of as frugality here is actually being done by slack: creating conditions under which you have enough flexibility to take advantage of situations when they arise and not be so attached to things as they are that you miss opportunities you value after taking. Only in your first case do I think frugality does the heavy lifting; everywhere else it is a way you created slack for yourself, but it could have been accomplished many other ways while living a more materially lavish life.