You would be able to supplement the ATV's capacity with one of those 40"X48" trailers. A few years back, my hunting party hauled out 350 pounds+ of boned-elk, 3 hunters (with equipment), and driver with my 2001 Honda 350 Rancher and trailer. It wasn't pretty; but a whole-lot better than walking (I plus-up the tire pressure during hunting season).
They can be modified for better cross-country mobility.
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I have the RTV now but sometimes, I still regret not bringing my trailer.
I don't have a dog in the fight nor do I want to recommend a particular brand/store, but I could PM you a link if you are interested.