S5-F1-C1: Determining an Individual’s Residence Status

you need to file tax return to CRA reporting world income. You will be credited for tax paid to the US, you will need to pay the remaining tax to Canada. E.g., you paid 25% of your income to the US, but if overall tax rate in Canada is 35%, then you will need to pay 10% to Canada. If you declare non-resident status, you don't have to file tax return to CRA, you only need to file tax return if you have income generated within Canada (such as rental income if you rent out your home in Canada).

if you still have significant ties to Canada, such as your spouse or children are still living in Canada, you cannot declare non-resident. But if you don't have significant ties, you are deemed non-resident even if you have properties, bank accounts, drive licenses in Canada. Deemed non-residents are treated same as non-residents for tax purposes.