I can only imagine what it would be like to live in something that compact. Even seeing a photo of a mobile home makes me claustrophobic. You might make use of the bench I mentioned in
this post.
If its affordable, purchase a few new pieces of furniture to replace larger bulky items. When my aunt move last year they replaced their end tables with chest style tables and put linens in them, she also bought several under-the-bed bags/boxes and stored things under each bed.