You can also use another encryption mechanism like GPG or something akin to TrueCrypt's (not sure how people feel about using TrueCrypt 7.1a these days) encrypted hidden containers to hold your KeePass database on your cloud storage, which itself would also be encrypted and need a key file.
This way you have three or four separate, strong barriers of entry to your KeePass database.
This way you have three or four separate, strong barriers of entry to your KeePass database.