in my opinion, this December will have the same cycle with December 2017, so that BTC will fall again to $ 1500.
If the price drops to $1500 then most miners will shut down their machines and we will see all time low difficulty.
Mining is almost profitable with the current price.
Difficulty wouldn't be anywhere near its all time low. It will never reach that level again because of how efficient mining has become. The hashing power of new hardware dwarfs that of the early days when people were mining with their CPU.