Travelling BKK-CAN-YVR transit time from Landing to onward Gate departure in Guangzhou is 25.5 hours

My 4year old son and I are transiting through Guangzhou from BKK on our way to Vancouverwe both are travelling on Canadian passports. Our flight arrives Guangzhou at 12:25 pm and since I didn't want my son to be too tired when reaching Vancouver we shall overnight at the Pullman Airport Hotel and scheduled to depart at 2:00 pm to YVR. The time from landing to take-off is about 25.5 hours but after clearing immigration we will be under the 24 hour limit. Will this work for us ??