If you're going to be on OHIP, then it would be very hard to satisfy the initial physical presence requirements, since it would require you to be physically present in Canada for 153 days out of the first 6 months of establishing residence in Ontario:
After that, it's to be physically present in Ontario for 153 days out of any rolling 12 month-period, which is doable by your arrangement, but the initial 153 days out of the first 180 days can pose a challenge.
Also, besides physical presence requirement, you also need to make Ontario your primary place of residence. I'm not sure how tough it would be to convince them that, despite being in the US for so many days within a week, you're primarily resident of Ontario.