That’s not a question with an easy answer. Every single gram that has to have delta-v applied will need more fuel, which needs more fuel, commonly known as “Th

That’s not a question with an easy answer. Every single gram that has to have delta-v applied will need more fuel, which needs more fuel, commonly known as “The tyranny of the rocket equation.” Maybe the crew metabolic efficiency drops the required resources to a level that one or more systems can change what tech they use (step change), pushing the weight even further? Without further information about what the systems evaluations are, what technologies this might allow the employment of, and a thousand other points of data there is no way to actually answer your question. EDIT: You added the part about vehicle sizing while I was replying, which is one of those thousands of data points. There are so many follow on effects it’s quite mind boggling.