Mining difficulty follows price, not the other way around.
If too many miners drop out, the difficulty automatically adjusts so that the block interval is still about the same.
It is elegant in that the more Bitcoin is worth, the more resources are put into protecting it.
Nice in theory, but there's massive lag in the system from the investments made in hardware. It might have worked out if people just switched on and off a few commodity hardware based systems, but when people started investing $10k+ in GPU farms and even more so with ASIC, the dynamics changed. Miners cant afford to sell at the market rate if its substantially below their projected cost base, so they horde until the price rises.
However, once that hardware is bought, the miner is compelled to keep it running even at a small loss to hope to cover the higher capital costs already sunk. So option 1 of the OP is unlikely. The high cost of mining does tend to underpin a price.