Nodes don't control the outcome, only hashrate does. Well actually the economic majority does. And the sufficiently organized whales are superior when it comes to a hashrate war (this was explained in great detail in the discussion between @dinofelis and myself in the other thread).
The nodes that refuse to mine on the longest-chain will waste their hashrate and bankrupt themselves.
What if BTC with PoW changed has the larger network, the Bitcoin devs, the larger transaction rate, and the larger market cap ?
Longest chain has nothing to do with anything in 2017, Bitcoin moved away from longest-chain = valid-chain a long time ago anyway, and given what I've described, even the chain with the most cumulative PoW won't matter.
Now, stop wasting everyone's time, you've already been told