If possible, I leave my deer meat in icy water for several days before I process it. Usually 3 to 5 days. I drain the water and add fresh water and ice every day. It helps remove excess blood and gaminess out of the meat. I know a lot of folks out west believe in keeping meat dry while cooling and aging, but cold water will cool the meat faster than cold air. (Also, cold air is usually hard to find in Louisiana) As long as the bloody water is drained frequently it doesn't hurt for the meat to be submerged.
Also, the deep freeze/generator combos will work if the meat is cooled properly first. I know some guys that lost a couple hundred pounds of venison by filling a deep freeze full of warm meat, plugging it in, and heading home across Texas. When they got to LA they had a nice frozen crust of meat, with a warm spoiled stinking center. If they would have cooled everything down with ice first they would have been fine.
Like the previous posts have said, big coolers, lots of regular ice, drain the bloody water frequently. All will be good. We brought back four antelope from Wyoming recently in one of cabelas 400 quart coolers. We just layered ice below and above the quarters of each goat we added to the pile. Took about 30 bags total to get everything cooled and kept cold for 6 days.