"Airforce1, descending to FL 270 due to icing"
If you are referring to the engine icing issue, there is a fix for that. It basically modifies the engine software to open the variable bleed valves to eject ice crystals. With that software change the limitation is much less onerous. Basically only applicable above 37,500 feet in areas of large mesoscale convective systems, typically found in the tropics. They are just waiting for further validation of the software change before full removal of the limitation.
Besides that, the 747-800 can use airports that the A-380 cannot.