The reason I suggested giving it away if the moving company won’t take it isn’t because it would be dangerous driving it up on his/her own. The reason is that they are bulky and space is valuable in the car when you’re moving.
If SF is like me, there is already a raft of things s/he plans on taking up in the car to keep the mover’s mitts off them. A propane tank would in no way make the cut.
(and I ditched a tank at a tank exchange station once, when we got rid of our gas grill. Never checked, but I would imagine they were glad to have it. It was in good shape and FREE)