I had a failure on one of my systems and had to re-install the OS. Now the 5 tasks it had downloaded are orphaned. These task's deadline in Feb 12, 21 which is a long time from now to sit unprocessed.

You can't.
The way to cancel tasks is to Abort them.
But that can only be done if you still have them.

These things happen now and then. Been there, done that, as they say.