Wireless ONVIF Camera Options?

I have a customer who has made the poor decision to not run cabling or conduits between his storage buildings. They have outlets in the soffit for cameras and its a small enough area to get good wireless coverage. My question is are there any reliable wireless cameras that support Onvif? No need to tell me how terrible of an idea this is I have shared these concerns with the customer but he has backed himself in a corner at this point.