Don't be so sure that all the high estimates have to be wrong.
"150 Million Adults Worldwide Would Migrate to the U.S" - gallup.com
And 150 million does not include the spouses and children of the "150 million adullts."
That’s worldwide. China being, say, 1/6th or so, would be about 25 million from China. Which is high - but not 100 million from just China.
There are reasonable numbers, and there are unreasonable ones. Saying that 100 million Chinese are going to just come to America is just not going to happen.
This number btw - is going to go down as time goes on. I know people say that it is impossible but it can and will. There will come a time when there is no immigration demand to the US whatsoever.