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.
As long as we look at Bitcoin for $, we will always be the loser. We should look at how Bitcoin integrates into our lives rather than USD value. Because the USD value sometimes increases and sometimes falls. However, Bitcoin and Blockchain continue to integrate into our lives day by day.