This was discussed some time in past history too. At that time someone suggested you tie a length of rope, cord, whatever around one end of the critter and do your best to hoist it up enough to tie it to one corner of the pickup bed ( or car trunk). Once secure pick the other end up and put er in !
I have, in younger days, taken and tied two straps around the buck's body, one at each end, then used them as handles. A big buck is still a big buck, but at least there are handles that way. Yes, hunting in Wisconsin, where you still primarily need to drag it out whole (that is changing however) , has its pitfalls.
ChuckC