Length of time Canadians can stay in US

I posted the following question in another thread but I don't think it got noticed:

I believe US allows Canadians to stay (live) in the US for up to 182 days before having to leave. Also I believe 182 days is per calendar year meaning you cannot restart the 182 clock just by leaving and entering US again. Am I correct in my understanding?

On a related note, since there is no passport check on exiting US or Canada (unlike most countries in Asia), how would immigration know how long a person stayed? If a person left US and entered Canada, would US get the departure date from Canada immigration (Canada entry date) and vice versa?

Not quite correct.

Anyone (Cdns included) can visit US for upto 6 months on B2 status (Cdns generally enter without a B2 document). This is negociated at time of entry. CBP can choose to limit your stay even shorter by issuing you a B2 I-94 witha specific date.

The key is one can visit for this long at any one stretch. One can NEVER live in US under this arrangement; one must always maintain a full-fledged residence outside US.

One can, at the end of this period, leave US and re-enter, starting a new visit (one can even petition by mail to stay an extra six months without even leaving US). This can be done the same day if you wish.

The problem however is that visting US for so long, or even trying to re-enter US soon after a long visit, will no doubt be met with skepticism by the border officers, not because of any yearly (calendar or otherwise) limt on number of days in US, but because it becomes doubtful at this point that you are merely visiting US, and doubtful that you are maintaining a viable cdn residence.