Even $100,000 would kill it. If 1 sat (or even 100 sat) == $1 then the fees would grind the system to a halt. The fees would be so high relative to the amount sent, that it wouldn't be worth it. From an investment perspective 1 sat==1$ is a nice round number. From a users perspective, only being able to buy things divisible by 1$ is crap.
if that happends im more afraid of the massive sell off , its going to push us down in a bear market once again, only if it grows slow and steady and not flying up this wont happend.