I am guarding against Ken's scenario because I have local in office backups, local out of office backups, and then the online backups. I have both enc files and II in all 3 locations. Unless my home and office are burglarized simultaneously, I have local data to access.
You can run AC without any II. I have a copy of AC at home on test computer where I would restore the enc file from the office, but not add the II. You can do everything except open II, which are obviously not present. It you try to open an II, you will get an error message, but AC will ignore it and continue. I think Jon's suggestion not to add any new II until the previous file is restored is the safe way to go.
