Miners might have to look at alternative energy. Maybe the big mining farms in the future will be run off huge solar pannels or wind turbines etc and generate their own electricity for free.
I agree with this, should probably use an alternative electricity or create their own power source for mining purposes.
But the total cost (machine+human+electricity) is the same even if all of us use cheap electricity. We will buy more machine to mine and total electricity cost will remain the same. If we have more efficient machines, we will also buy more, the result is the same. The total cost of mining is more or less same as the block reward including fees.
New generation miners will become more efficient reducing the amount of electricity needed.
Bitcoin mining farms will also be more often powered by hydro-electric/solar/wind power, also reducing the negative CO2 emissions related to bitcoin mining.
If the price rises as you say, then difficulty will rise accordingly, but the mining profit margins will remain razor thin, meaning people will have to become more efficient somehow.