Can I use a use WiFi range Extender as a wireless network switch? Ex. Camera upload footage to hard drive.

I know it won’t have the ability to connect to the internet with this method.

Is it possible to use a range extender as it’s own network instead of a repeater for a router?

My end game is to set up some diy raspberry pi zero cameras around the outside my house and I would like for the footage to be stored on a hard drive connected to a raspberry pi 4 within my house.

I would like to not use my WiFi connection because in the event my WiFi connection went down I would like the footage to continue to be uploaded from the pi zero to the hard drive and range extenders only need electricity.