I'm gonna piggyback on OP's thread because I'm not there yet - and that terrifies me because not being able to sleep well in a tent really limits your DIY elk hunting options - but here's what I have found thus far:
-Ground must be flat. Not just close, but flat-flat.
-I can side sleep in a large mummy bag just fine, at least as far as the bag is concerned. But it has to be a larger bag.
-I still need my knee pillow or some good substitute for it, like a balled up piece of gear, ideally stuffed into a 'stuff sack' so I can use it like a pillow and have it roll when I roll. Easy with a pillow, hard with a balled up jacket.
-Ear Plugs are an absolute must. I've even thought of adding muffs over the plugs.
-I've slept down to ~25 degrees in my cheap 0 degree bag and it was just fine and I honestly think I could have went down another 10 degrees or more without adding a blanket, and I believe that a thin puffy style blanket could easily add another 10 degrees to that, and a large one could be shared between 2-3 campers.
-A good pad ('good' meaning it doesn't compress enough to let your butt touch the ground anywhere and is thick enough that your butt doesn't get cold) is absolutely vital.
My biggest problem: noise.
I could turn a single night's campout into an essay on noise. Dogs, teenagers shooting guns at the old bridge down the road, roosters, coyotes, owls, helicopters, and if the tent isn't very well staked down sometimes a breeze makes it flap and when that happens I am wake right up. Sometimes our cows/pigs/goats make noises, especially the night we camped after the snow/ice we got a few weeks ago. Cows walking near you on frozen ground make sleep impossible.
I've heard that Colorado mountains get downright quiet in October at night, but have yet to experience it from inside a tent (ETA: At least not recently). Of course all it would take is a single bear snuffling around at 3AM to ruin my night.
I have considered getting a tent then pitching a floorless, larger tent over top of it - I don't mean the two-layered tent designs. I mean, do the usual mesh tent with a rain fly of more waterproof stuff, *THEN* put an open-floored, heavier, less breathable material, outer shell over that. If it condenses much- and I don't think it would be bad in the dry October air - it should largely leak down the sides of the outer part and not be a huge bother. The inner part should stay dry, should be a bit warmer with the outer shell slowing air/heat movement, and if anything perhaps the extra layer would make a quieter sleep.
Also, I have considered some sort of way to stretch a thin sheet maybe a foot above my head, to retain at least some part of the warm air I exhale, so my face isn't cold. The cold face doesn't stop me from sleeping, but when I wake up, I always notice it. It's not a danger, just an annoyance at 3am when you'd like to go to sleep again.