I totally feel your pain, except I did a coup - I claimed our sons room for sewing a year before he moved out. Then bought a long arm earlier this year, so that there is not any "extra" room in my sewing room for any of his stuff.

He has the entire basement - pool table, weight lifting room, a room for stained glass (I did the classes too and loved it, but dad died and then I found quilting). We are also storing my mom's "stuff" that she can't part with, but will never use again - she is now in an assisted living apartment. We have a ton of stuff from his mom who died last fall. We have a ton of our own stuff, since both of us are keepers, but not hoarders. We tend to tuck things into the basement, but the rest of the house except for closets are ok.

We have contractors coming tomorrow to start on the kitchen and hall bath. I have been pitching stuff as well as donating usable stuff from our son's room as well as the kitchen and bath. In order to have room for the stuff we are keeping, I keep trying to get rid of the old stuff. I think the stuff he packed, he just packed and did not sort through.....

I think we need to move all of the furniture in the living room out of the way and at least cover it with blankets and put up some kind of tarp or something in the hallway and to the sun room or everything will be ruined by the dust. He thinks I am over reacting.