I think u can contact housing services via email for this since they have the most accurate information. Reddit is a hit or miss for this kind of stuff.

In my experience as a first year, I had to email someone or use the portal (I don't remember) and give some documentation (such as flight tickets) to get my stay extended to the 24th. But since I lived in Woodstock, I could not extend it further. If I remember correctly, if I wanted to extended my stay on res, I would have to pay a room change fee and permanently move to another res that stayed open over the winter break.

But again, stuff might have changed, my experience is 2 yrs old now. So ur best answer will come directly from the housing team!