Hi Roger
You may already be aware of this, but
Camranger offers some WiFi functionality, albeit for approx. US $300.
“
CamRanger is a stand-alone device that connects to select Canon or Nikon DLSR cameras with a provided USB cable. It creates an ad-hoc WiFi network that your device (iPad, iPhone, iPod Touch, Android, or Mac or Windows computer) can then connect to. The free CamRanger app then enabled control of the camera. There is no need for a computer or existing Internet connection.”
Cheers
Dennis