Don't try to reason with an unreasonable person, the hoarder. Call your own shots and do what you need to do. If you factor in a bunch of input from the illogical problem source, where do you think you'll end up?
Either subject yourself to it and accept the work or don't, but trying to work with them will derail your efforts.
No, it's not your direct problem, but given that you say you cannot move for whatever reason, you seem to yield to it being your indirect problem.
Your motivation is cleanliness, space, and new beginnings. Everything that comes with those. If that's not enough for any of you, cozy up with complacency until you can move out.
time for the talk again