RLA, that is one way. I carry rope to do just that if needed.
I also carry (in the truck)a couple straps, and have even used two strap-on tree steps, to make a band around the deer's body (chest and near the rear quarters. Now I have handles !
Of course, a thinking man would have a 2' wide piece of 3/4" plywood to lay like a ramp up to his pick up bed, then use a come along or similar to winch it up.
Of course, some of the deer I have killed were picked up with one hand, so that makes it easy. They sure made some fine eating though !
ChuckC