Powerwinch wiring question - 12 Dec, 2018

Just got a new 4Runner, and I would appreciate some help or suggestions with the wiring harness for the powerwinch on my boat trailer. My old 4 runner had a hole in the tire jack compartment (on the driver's side of the rear cargo bay) which allowed me to snake the wiring harness from underneath the truck to inside the truck. Any time I needed to pull the boat up onto the trailer at the end of a fishing day, I opened this compartment, and plugged in the jumper portion of the harness to the socket on the powerwinch. Was easy and effective, and out of the way when not in use. It was also protected from the elements, tucked away in this compartment. 

The new 4Runner has no such hole in the tire jack compartment. I've tried everything and have come up empty. I used a snake, flashlight in the dark looking for the light coming thru somewhere, and a sinker on fishing line without success. I really don't want to drill a hole in the carpet or keep a spare 12V battery back there either. My other option is to fit the 6 foot jumper cable with a male plug on each end and wire the harness to a socket on the bumper, the hitch receiver, or the hitch bracket assembly (haven't figured out where yet...). Each time I want to pull the boat out of the water, I plug one end to this socket, and the other end into the socket on the winch. Obviously, the socket mounted to the truck would already be connected to the car battery up front via the wiring harness underneath the chassis. 

Sounds complicated, but I'm trying to make it as simple as possible. Any constructive suggestions or help would be much appreciated. I guess I could also take it to someone who does this kind of thing for a living, but I'd like to try and do it myself.

Thanks in advance!