Aeroplan Award Ticket - Overnight in HKG
 

I've booked an Aeroplan Business Class Award ticket that has me landing in HKG from YVR (Air Canada) at 17:05 local time. I then leave the next morning on Singapore Airlines at 9:05. Not sure if it matters that this is Aeroplan booking, but will my checked baggage be checked all the way through? Or will I have to retrieve it in HKG?

You claim it in HKG (AC checks it to HKG), and recheck your luggage in the morning. I just did it two days ago. In HKG, there is no transit hotel in the air side, and likely you need to clear the custom and immigration staying in Regal Airport Hotel (my routine), so I doubt AC allows you to leave the checked bags inside the airport and get loaded to the connecting flight, in case you do not fly in the morning.