I usually take at least two coolers and a box of gallon zip locks with me to the woods. I keep ice in both of them. One is full to the top, the other just has a couple of bags in it to keep it cold. IF I get something, I get on ASAP skinning and quartering. I put the whole quarters straight into the chest that only has a little ice in it, then add the trimmings in the bags around the open areas, then add ice as needed to form a layer. Once I fill one, if needed I start on the other. Where we hunt the chances of getting a hog(s) is about two to one of getting a good deer, so I come prepared.
The old fridge or chest freezer is great. I had one sitting on the back porch of our place in the country with six 20# bags of ice in it. Last trip up we actually got a hog and when I opened it up, well nothing but water and funk. I guess all good things come to an end. I had it set up with wire baskets that allowed us to stack in hams and shoulders on them and let the air circulate around them which cooled them quicker. I kept the thermostat set to around 30 degrees so that it would chill really well but took over night and then some to freeze stuff solid.
Another option is to simply take it to the closest processor to put it into their cold storage locker. That will usually only run $10 per night or so, sometimes less if you know the fellow your taking it to. I did that with my mule deer when I was in CO, and it only ran me $30 for a 4 day chill. It gave me time to hunt another couple of days, and then get everything ready to bring it home, plus pick up some dry ice to put on top for the trip home. Where we were at it was close to an hour one way to go get ice, so the storage was well worth the money.
Like mentioned above, I do the shooting, and cleaning and the wife does the cutting and trimming and she likes it solid so it holds it's place and don't get all mushy while she is working on it. That ol freezer had been passed around to at least 4 other people before I got it and set it out there close to 5 years or more ago.
If your in a position to hunt hogs and deer in the heat, it is something to possibly look into. Even purchased new a small one isn't that expensive when compared to spoiled meat or the cost of a couple of trips tot he processor even if it is to simply put it cold storage for a day or two.