1996 Polaris Indy Lite

Well, you might just want to bite the bullet and find a utility sled, like the WideTrack. I've never rode an Indy Lite; I hear they're a fun little sled, and they're very popular as a starter sled for kids. That said, it definitely doesn't fit the bill if you're trying to haul anything or dealing with deep snow. You are correct that a mountain sled wouldn't be ideal for this either, although at least getting stuck wouldn't be a problem. The thing about something like a WideTrack is that they have a longer, wider track than most sleds (156x20 on newer ones, as compared to 121x15), plus low range (great for pulling a carcass) and reverse.

If you're intent on buying one, you may have to travel a little farther (try putting out a "wanted" add too though). Otherwise, depending on how much you'll end up using it, I'd seriously consider renting if you can work that out. If it's just for an annual trip, I don't think you'll ever break even buying one, and you have to worry about all the maintenance and storage, plus hauling it to WY and back.

If reverse helps when you get stuck, you're not stuck.
Pretty obvious you haven't really ridden before. Do you know where you'll be riding, as in how much snow and what kind of terrain?
You mention riding slow a lot and obviously the elk aren't laying in chest deep powder waiting for you, lol, but do you have to hit some real snow to get where you're going?
If you do, those 2 sleds you posted are about the worst choices. If you aren't hitting deep snow, get the Indy, but realize you'll be riding a clown car unless you're like 5'-4 and a buck40 soaking wet.

If you're looking for a no frills sled with fan cooled reliability in low snow, decent track in powder yet cheap, easy to get unstuck and big enough to haul you around, think 550 fan cooled sleds.
I got one for sale that would fit the bill better than either of the ones you asked about, if you don't find one.

I used to cruise timber in NE Washington, Northern Idaho and Western Montana in the winter. We had two sleds to use. A 440 AC Prowler which had the zing on packed trails but sucked everywhere else. The other was a 440 Bearcat utility. It had the gearing but was way too heavy to get unstuck. We kept running across a guy out of Missoula that had a Skidoo tundra. That thing was awesome. It was underpowered compared to what we had but it was so easy to maneuver and get unstuck or over logs that the guy could handle it by himself. We were simply amazed that it was more like a pair of motorized snow shoes than anything we had seen.

I have a '94 Indy Lite that I extended with a 136" track that works very well that is actually for sale, but I would look for an older Tundra if I were in your shoes. They even had the electronic reverse.