The major question I have about this is will we be required to empty our house (furnishings etc) beforehand?

I recall this being the case if you wanted to demolish private rooms before leaving an FC - you had to empty it first..

Is this still the case? Will we need to find 400 inventory slots before 4.1 to store all our furnishings?

I know no one knows the answer yet.. But I am hoping we get one before 4.1, so we don't go to relocate and find out we have to remove everything manually.