I was going to recommend the thread below, but I see you started that one back in February. So confused about the need for this duplicate thread.
I agree with their recommendation of a powerline adapter with built-in 802.11N WiFi at the far end (in your barn) like they show in the second post there.
Did you try that?
Basically, it would look like this. The barn is to the right, and the mobile devices shown there can be your Wyze cams. That would be the network you set your Wyze cams for:
