As usual, CBC makes the mistake of identifying a good point - that there are reasons why many polls are not reliable - and then fails to acknowledge that the problem affects polling relied upon by both sides. If Trump thinks he has polling that is infallible, he is surely wrong. However, if the Clinton camp thinks the NBC, Monmouth or other such polls are reliable, they're also kidding themselves.
People: a) have stopped answering polls, particularly when they are aware of the controversy surrounding the choices (and there is no question that supporting Trump is seen by the media as the more controversial choice, and b) no longer feel compelled to tell pollsters the truth. Gone are the days when people trusted strangers who call them on the phone.
Further, turnout is going to be a big part of this election, just as it was in Brexit. Yes, the Clinton camp has thrown a lot more money into its ground team, but the Trump supporters have been highly motivated by their perception of collusion between the Clinton campaign and the media, and were highly agitated with the course of government before Trump even ran. I would predict much higher turnout rates for Trump supporters as well as much higher rates of voter registration problems for Clinton supporters. Will it be enough to offset what most polls are saying? I think that's impossible to predict, just as it was for those following Brexit.