Doesn't sound as if you have seen Cade return to the nestbox very much lately, TPC. Am I right about that?
Everyone was at the nestbox on the 4th when Ivy dropped off food. They don't need the food much now based on how little they actually ate of it, Princess turned up a bit later and took off with the nice size leftover. The chicks are a month flying so they will be starting to hunt on their own at this point, will need some supplementing from the adults but they are well on their way at this point to be totally self-sufficient.
Remember, Hurricane, Trey, Alley (Lincoln, Nebraska), Radisson (Edmonton), T2 (Brandon) among a long line of others were not big visitors to their nestsites once they fledged either ...