I was on a circle pacific ticket back in July where in between my last two sectors I had to overnight in SIN on a QF-CX connection as a result of the QF A380 flight arriving into SIN late in the evening. As a result had to overnight at the transit hotel before catching the CX flight the next day. No problem. QF tagged my luggage all the way to HKG and I didn't need to retrieve it in SIN. If QF can do this on a long different day QF-CX connection, I don't see why it should be a problem on a long different day CX-CX connection at their own hub.
I rarely make flight connections in HKG since whenever I fly there it is mostly my final destination, but OP should be fine.