Well the difference is that they're more likely to notice, that's the risk.
Correct me if I'm wrong but prior to 1986 it was actually legal for Canadians to do this, they could get a "Canadian resident permit" or somesuch. I dimly recall lots of complaints when the law was changed, and the INS promised to tread lightly when it came to Canadians, which is what USCIS still appears to do, but of course 1986 is a long time ago now and memories are fading.
I remember back then the INS were actually a bunch of reasonably helpful bureaucrats, now the "CIS of the DHS" appear to be a bunch of facist automatons, they appear to have been given specialist training in being extremely unhelpful.
I have a great deal of experience with facist automatons (the police in the UK), but I'm afraid even my bullshitting abilities may not match up to CIS, which is why I don't risk buying a property in the US until I've got the cash to maintain one here.
When you roll up to the border, you can't just say: "Oh, I've got a house down there, I'm just going down to defrost for awhile."
You have to say something like:
"No, Mr. Facist Automaton, I have no intention of residing in the US at all, in fact I will spend every moment I am in the US sitting in my temporary abode, scratching my nuts and dreaming of the day I can return to the socialist paradise that is Canada, in order to be sure that my igloo has not melted, my health is in order via our wonderful healthcare system and to sustain myself on chocolate bars that do not taste like reconstituted vomit. Oh, and by the way, thank you for being our closest ally and not trusting us to live in your country."

Steve.