if the same passengers want to travel on a J round trip anywhere internationally, anytime within a year of original travel date, there is no need to change/cancel/redeposit points...

destination can be changed (with no refund if new trip would have cost any less miles) as long as first segment has not been flown.

although you will pay a change fee per person per direction, potentially this can also save you the award redeposit fee plus save you from paying a phone booking fee if your new trip would have been too complicated to book online.