My parents are in Canada presently on visitor visa.The validity date on the visa is of 2032. They arrived in late November 2022. Their passports were not stamped with any dates at the Toronto airport, but I guess they can stay till 6 months at a stretch, which would be May end. However, I would like to increase their stay by another 3-4 months. Wanted to understand how to go about it and if I can start the process now or wait till April end to start the process? Thanks in advance.