My recommendation would be neither, having had an experience with the exact same thing. The cable that comes with the Yi is about 7 ft long (2.1whatever mtrs) We had a couple doves nest in a pine tree in our back yard, wouldn’t it be neat to watch them hatch and raise a family, well grab one of my cameras that isn’t watching anything important cut down a mount that wasnt used and proceeded to mount the camera to the tree, worked great so now get some power to it. My distance is give or take about the same as you are looking at. Plugged the converter into the outlet on the side of the house and dugout a 20 ft extension so now i have about 8 meters good enough (not) can’t get the power down the line, just too long.
Solution: Yup have one. Go down to your local hardware or Walmart if you have one where you are, and buy a simple 2 wire 18 gauge power extension cord as long as you need it. run that for your distance plug the adapter into it and the Yi usb cable in, you will be good to go, 18 guage will be overkill for the amount of amperage the Yi draws and you don’t need grounded. With this you could probably go 50 meters, OK might want to go to 16 gauge to cover any loss. Anyway have some great pictures of baby doves…watched them grow up. These are great cameras for the money