Phone migration

If the plan is cancelled, No, you can't. You would have to reactivate with a plan and pay for 1 day of service. However, it is also depends on when you cancel the service. When did you do it? And did you have an overdue amount?

I have nothing more to add and I cancelled on January 4th. Where or how can I pay for just one day?

I assume you are a postpaid customer? You will have to schedule a call back from Koodo and ask a rep to activate plan and number for you. The problem is they might charge you a connection fee of $80, so make sure you ask if they can waive it first.

I am a prepaid customer.

For prepaid, you have to reactivate using a cheapest plan though and be charged for the full month. There is no option for one day service.

Anyway, You can try to use Koodo for 29 day then port out on the last day.

And actually, there's some information I need that's also important. Can this be done online?

If you are comfortable, you can ask here. Please don't post your personal information