Also If you say it would hit as low as $300 then a lot of miners would probably stop cause that means their payment just got halved, why would they continue? That being the case, bitcoin circulation would be more difficult.
That's just a simple answer because for defining doing the mining is not profitable in this time a lot of people just considering from 1 perspective and they're not considering from the another reason from halving.
If your electricity price is low and heating is not a problem, you can continue mining. It is still profitable.
