Pretty much this.I think the 2-hour rule was aimed at the people who get reported for drunk driving, but manage to get home, before police can nab them. I don't know how frequent this scenario is, in real life.
Re, the Global news story (the Art fellow), police don't need a specific reason to pull you over, while on the road. There's case law that states police can pull you over to check your driver's license, without any reason for doing so. So, when Bill Blair was saying that police still need to comply with HTA before pulling people over, he was just gesturing.
Unfortunately, this added power can be used for all the wrong reasons, like this former York police officer, who ended up serving time.
Outside "hot pursuit", I'm not sure how officers can check sobriety if someone enters their home, already. Unless they get invited in, they would need a warrant. Consider a situation where person who lives alone, drives home, binge drinks for 1 hour, and then passes out. If he is not physically able to answer the door, the only way for police to enter, is to break in, force wake him up and have him do a sobriety check. Not sure how that would play in court...
Someone can correct me here that Police cannot go on a fishing expedition if they pull you over for a document check. Unless it was something obvious (bag of drugs on the car seat, obvious signs of impairment), it's a thanks and cya later deal.