Ha, ha.
Good question!
The honest answer is: "when I am not feeling too lazy to do it"!
The problem is that there is no longer a clear path to get to it to clear. When I was using the ATV and walk behind blower, I would keep the sidewalk along side the house going to it open. Now that I use Big Red, I really cannot clear that area, as there is a bit of a hill at the beginning that is just a bit too steep for Big Red/blower unit. So I have to climb over the snow that has dumped off the roof (currently around 4-5 feet deep) and then grab the roof rake and clear. So it takes a bit more prep (putting on boots, gators and proper pants) just to get there. I am trying to figure out a solution. I might even be able to sneak around the back side of the house. I wish I could train Huck or Millie to do it, as they love to go back there. Perhaps a hydraulic lift to tilt the platform to clear it?
-John