This is way outside my field of study. But my thought, for what it's worth:
There is no way to successfully date the Biblical account and the various flood myths. All dating is based on speculation and on preference.
Could the 8 survivors noted in the Genesis story refill the earth? Given prolific reproduction [no birth control is a factor here], yes. Whether that could happen in the short time the Bible seems to allow, I do not know. That would take some mathematic calculations based on tones of guess work. But I think you could construct a model of population growth over time. Anyone truly ambitious?