Oh, yes, very easy Fit MOO. I uploaded a pic with various size coolers as an example, person standing in front of coolers gives you an idea of sizes.
So, I'll speculate liberally regarding coolers.
Everything in this post is imaginary.
BM was evidently a hunter or liked to hunt or thought of himself as a hunter. Anyone in any of those categories is going to have a cooler large enough to handle the "kill". Out west, the "kill" is very likely to be bulkier than an average woman. From that, I would surmise that a) BM had a large cooler on hand and b) a woman would fit in it.
I'm guessing the size of head and antler rack at least at one time gracing the walls inside BM's home would be at least the aspirational size, if not reality.
[Did someone mention upthread that there was a roadkill deer head with antlers outside? Maybe to reinforce "if you find a cooler with blood, it's because I'm a hunter". Another deflecting clue. But this is TOTAL speculation on my part.]
So, yes, there was very likely a large portable cooler at hand (I'd guess you'd keep that kind of thing in a garage?) and maybe even practice loading it.
Come to think of it, ice might have been needed on Mother's Day weekend and may be the reason for a "shopping trip". Depending on timeline, new loads of ice might have been needed to minimize aroma.
I wonder if a cooler leaked into BM's truck?
And here my imagination might be totally running away with me.... Supposing you were at a job site, and shortly after you got there, the day heated up (it was forecast at 90 degrees per
Denver weather: Sunshine Sunday before a slightly rainy week), and you went to your truck, and oops, your cooler was leaking, and, was that a smell you smelled?, and dang if you forgot to add ice to the cooler..... I think you'd tear out of that job site even if you'd barely got there. And you might be too spooked to come back even after you picked up fresh ice and even though you'd barely done any work that day....
Oh, gosh, my imagination is jumping all over the place at this point.... wasn't there a place by the river at the job you were working? What if you washed your truck there? You had a gal working for you, you could even have her do the tidy up after you cleaned up the truck, raking 'n' all to make it all look nice and professional....
My whims are totally taking over me here.
Take this post as hypotheticals. There may not even be a single grain of fact.