i've keep uncleaned fish for 4-5 months without any problems...........but they were all frozen. i was told long ago to keep fish from freezer burn not to clean them until you need them. i've since tried and still do freeze whole fish when i am too tired to clean or have too many to clean. just rinse and packed them to the freezer, thaw in water and you have fish that looks like they were just caught that day.

as for keeping fish uncleaned and not frozen, i would say 4-5 days with ice and keeping the water/slime drained out.