Also, my interpretation of the 183 day rule is different than yours. If you don't meet "significant" or "secondary" ties to Canada (per the link I sent), then you might not be a resident of Canada for tax purposes, unless you spend 183+ days in Canada, then you become a resident for tax purposes. In other words, the 183 day test becomes the trump card. You see it the opposite way - that "significant" and "secondary" ties to the U.S. becomes the trump card.
Thanks for the information/contribution to the discussion. From my understanding, if it is only a temporary situation (if I spend less than 183 days in Canada, working for an US company), I am not a resident of Canada for tax purposes, right?
Also, does it matter for how long is the US job is "performed" on Canadian soil? Let's say that I work remotely for an US company under H1B in Canada for 2 months, should I declare that amount to CRA?
Thanks.