The miners can only ignore transactions that don't carry a fee or a fee that isn't large enough. But other miners will likely accept those transactions, so the miner isn't forcing the fees up but instead letting them pass him by.

More likely the inefficient miners will be forced to quit mining as they will not be able to compete with those who either don't pay for power, or are not a commercial endeavor that is doing so at a larger scale.

Whether that is two months or four years away, who knows.