Rule of thumb is that you need to get that meat temp below 45 degf. Like BBJ said, if it' s getting cold at night you should be ok for a couple days if you keep it in the shade during the day. Bring along a big container of ground black pepper. If it' s warm during the day, the flies will egg up your meat if you don' t keep them off. Rub the qtrs down with ground black pepper right after you skin it to help keep the flies off. As long as you can keep the dry it' ll skin over and be fine for a couple days. To haul it home bring along a couple BIG coolers and throw some dry ice on top of your meat. I usually put some newspaper or something similar between the dry ice and the meat (if it isn' t cut and wrapped). Dry ice will freezer burn your meat if it touches directly on it.

Good luck!