It sounds like you need a new truck, not a quad with tracks.
I wish you luck but if you are hauling any amount of bait and loading coyotes I really don’t understand how you’d ever have enough room to load everything under a deck. I don’t even want to imagine loading roadkill under it.....what do you do, push it on? Then you have contorted coyotes to load under there from the end. Maybe if they freeze standing to attention they might load better.
I do run and gun coyote trapping with a lot of loading and off loading the sled. When there’s lots of snow it’s easy to back into a snowbank and back the sled off. When there’s not though, I have a half sheet of plywood in the box to use as a ramp (pretty high tech). It’s a pita when i’m Catching coyotes because I have to put the plywood on the bottom and the coyotes on top......always loading and unloading coyotes to get at it. This is the type of thing that I imagine happening with a deck with sides if you are loading coyotes in with the machine......unload Yotes to get it off and reload once it’s back on. Who needs that?
When the snow isn’t that deep I can drive to almost all bait sites and I don’t have to bother hooking up the trailer/sled.
Trailer for machine and box for bait and coyotes gets my vote.