I was overnighted once by CA on a missed INT-INT connection in PEK. Even on a J ticket, I felt the hotel accommodation was not up to Western standards. Transferring between the hotel and airport was also a PITA, which made the idea of taking the airport Express for a quick jaunt in the city less appealing. But that was four years ago and things may have changed.

Also, there are many other U.S.-bound flights later in the day (to LAX at 15:00 and 21:00, for example, plus flights on UA, AA, DL) such that, IMO, an overnight reroute/reaccommodation is unlikely. If your flight appears destined to misconnect, from my experience CA staff will have already rebooked you by the time you land in PEK.