Primarily, the large die-off will be in places which are pleasant living now, coastal cities, or river basin cities. These cities grew up where commerce was available, and the heavy die-off will be there. Since the waters rise, it will become fish food. In other areas, cities high in the hills, obviously, this will be a reeking mess. Nature takes care of this, in short order, within months, through bacteria and bugs. If you really want to know how to deal with it, get some chickens that eat the bugs and send them out there to fill up, and then you can eat the eggs. Just stay downwind of the stench. This is not exactly socially proper advice, because people want to bury their dead. Most of the dead will be under buildings or trapped under water somewhere. You have to do a mindset to think of the survivors. Think of the living who are feeling pain. Your obligation to the dead is only a ritual you can put aside.