the Government should have is a plan of concessions based on each set of votes it thinks it will get. So there is a bottom line, which narrows with each vote.
If the vote does not narrow then the Government must either accept the amendments or withdraw the Bill because they have no ability to force it through without the Parliament Act.
So Sunak could be really beaten if those numbers do not change. He will have to give way. Usually a government will avoid anything but that because it means they have lost all power in Parliament.
This makes Sunak's statement today very odd. If he really believes it, of course.