Residency Starting Date under Green Card Test

[hgen]

Hello,

I am a Canadian citizen who works for a Canadian employer, but who became a permanent resident of the USA in 2016. I do not own property in Canada.

- Jan 1 to May 15, 2016 = I was in the US as a visitor, working remotely for my Canadian employer (my salary is deposited in a Canadian account in Canadian dollars).

- April 8, 2016 = Bought a vacation home (condo) that I rent out as a vacation rental when I do not use it.

- May 15, 2016 = I returned to Canada where I kept working for my Canadian employer and where I rented an apartment.

- July 1, 2016 = I entered the USA with my permanent resident visa in my Canadian passport (IR-1) I had received from the US Consulate in Montreal and stayed four days for a visit and returned to Canada.

- Sept 2016 = I received my Green Card at a US address (someone received it for me) and I had it sent to me in Canada.

- December 14, 2016 = Ended my lease in Canada and I moved to the US with my Green Card, where I still work for my Canadian employer remotely (my salary is deposited in a Canadian account in Canadian dollars)

Now...

1) I do not meet the substantial presence test, but do meet the Green Card Test for 2016. However, what would be my residency starting date under this Green Card test? July 1st or December 14th?

2) Whether the date is July 1st or December 14th, would I have to file as a Dual Status Alien?

3) Should I be filing as a dual status alien in the US and as a deemed non-resident of Canada (start of the deemed non-resident status in Canada would be my residency start date in the US)?

4) Dual status aliens who are resident alien by end of year can elect to be treated as resident aliens for the entire tax year if they have a US citizen spouse who resides in the US at end of year (my case).

If I do that, does this mean I can file in Canada as a deemed non-resident for the entire year, by virtue of Art. 4 of the Canada-US tax treaty (since I have property in the US, despite having an employer, bank account, pension, family and social ties to Canada?

Any insight would be greatly appreciated!

[hgen]

I should add that the condo I bought in April 2016 is in the US, not Canada.