Motion App does a good job of this. It helps will longer tasks that you'd want to split up over a couple days or even a couple weeks if not urgent. You specify the estimate task time, then specify what minimum chunk should be. Example, if a task takes a few minutes to get in the groove you might want to set a minimum 1 hour chunk, but if it's something like data entry where you can jump in and out, you might set the min. chunk to 15 min. Right now there is really no useful way to manage longer tasks in Ellie (AFAIK).