I will keep them until the price will go to the rise
and what if it will not rise anymore, and it go near the point of no return, like sub 10, or 1 or even zero?
another important aspect it's the time required by the value to drop like this, if it happen slowly, there might be a recover, but if it happen to fast miners will leave the network
if it is severely drop in price, I think a lot of people will buy it, and the price will restore to the initial value
IMO very small probability that the price falls below $100