Because we shoot at 20 yds and 25m we want to avoid fixed monitors with trailing leads etc. - We are out in the sticks so no internet or phone connection available.
Is there some sort of camera/baby monitor system where we could have a wireless camera tethered/hotspot/bluetooth linked to a simple tablet or even your phone?
I've made wired systems:

Camera through spotting scopes:

and wireless cameras using RC drone type video transmitters:

I'm really looking for some sort of "off the peg" system that won't cost an arm and a leg - I'm fairly dim about this sort of technology - any ideas?