This is aimed primarily at Ex, but may be somewhat useful info for everyone.
Sounds to me like the guy in the truck containing your package didn't follow procedure. I order a lot of stuff from overseas and had to pick them up personally from the post office, so I've become pretty familiar with CP's methods.
When a delivery attempt is made but not completed, the person responsible on that route must bring the undelivered packages back to a nearby postal outlet to be held for later pickup. From that point they are entered into that outlets inventory system and the status updated on the CP website, where it should read as being held at said facility for pickup. This is supposed to be accomplished before end of the same delivery day. Not to mention that they are supposed to leave a failed delivery notice at the time that delivery was attempted. Although sometimes these notices arrive the next day (lazy driver, or no pen/slips).
My guess is that your package is either sitting in that same truck (unlikely), or has been dropped off at a local postal outlet and not yet been entered into their system (likely). My local outlet is on the ball the majority of the time, thankfully. Anytime I have received a slip saying my item will be available for pickup by 1pm the next day, 9 out of 10 times it's available for me to pickup the same day around or after 5pm.
Give the outlet(s) in your area a visit and see if there's a parcel waiting for you there. So long as you have valid ID with your current address, they should release the parcel to you without the delivery slip. I myself have had a couple of instances similar to yours where the tracking info just seemed to stop. I went down to my outlet, had them dig around a bit, and they pulled my package out of the pile. God knows how long it would have sat there for if I waited on updated tracking or a failed delivery notice.