Use iCloud only for backup - keep all files on hard drive

I frequently work in a space with no internet, and want to have access to all of my files without a connection. I have followed the instructions but I still frequently try to access a word file I haven't opened for a few weeks and see the cloud symbol, no file. I have 170 available of 245 gb so there is no reason for this. I work on two different computers (desktop with big screen and go-anywhere laptop) so the sync feature is very helpful but not if I can't get at my files when and where I need them!

How can I keep my files on both of my hard drives and just use iCloud to sync them?