I am not sure what you guys mean by disturbing the icing but here is what i do:
make 2 of my batches and transfer them to a big rubbermaid. cover the surface with plastic and put top on. I might make it 2-3 days before doing cake. leave at room temp. when it is time to ice the cake, i open the rubbermaid and ice straight from there. it is still smooth and perfect as the day i made it. When i ice the cake, the excess i scrape off while smoothing, etc goes into another bowl, not back into the rubbermaid. The scraped off icing will be kinda crusty and airy. I save that for borders and filling OR if i save enough partial batches of that stuff, i can fill the mixer again, and remix till it is smooth again.