Hey! I'm still waiting for their email invitation to oath so I can reply them to ask for a change of date. I expect them to email me a week before the scheduled date (so around Jan 30, 2026, I will already be outside of Canada at this date).
I learn that they have very clear instructions on how to ask for a reschedule, so we only need to read it carefully and follow the instructions.
As I see from my friends, they take 1-2 days to respond back (but for some other people, they never receive anything)
Intentionally taking the test closer to the deadline - that's what I thought of as well, but I didn't do it in the end. I think that can be a good strategy; and even if you receive the oath invite while you are not in Canada, staying with a loved one is a very reasonable excuse and IRCC will have no problem with it (in my opinion)
I hope your mom will feel better soon, sending prayers your way!