I can't imagine how one or two adults could push a rolled over vehicle onto its wheels again. Most of the time a vehicle rolls of a road in wildland terrain it stops rolling because it jams up against a rock. log, tree or into a depression and not because the roll motion has expended its energy. The pictures I've seen of the vehicle show it downhill from the road and if it didn't get jammed it would have rolled further downhill. If its jammed then rolling it over would be difficult, if not impossible. If it is not at the bottom of the hill it would be dangerous to attempt to right it as it could roll over or back onto those who are trying to upright it.
Being able to sleep on padding is the least of one's worries in a situation like this. Keeping warm and hydrated and warm are the priorities. Hypothermia can occur in temperatures as high as 45-50 degrees. Yes, in wet conditions some people have died with temperatures in that range. Second is staying hydrated. A person can live without food for a couple of weeks, can live a couple of days without water, but can die in minutes to hours from hypothermia depending on temperature, sunlight and moisture. The driver kept focused on the two most important factors for survival.
Expending energy doing anything that doesn't contribute to warmth or cooling (depending on location and time of year) or to stay hydrated can be dangerous. In most survival circumstances the energy budget is very limited and if an effort wastes it on non-essential activities it could result in death or significant injury such as irreparable frostbite damage.
If the padding could help keeping people warm it could be cut off the seats without trying to flip the vehicle. With all due respect, I see trying to right a rolled over vehicle as a bad move. Even if it could be started again trying to drive out of the hole this vehicle was in would not likely succeed.
This man did exactly what he needed to do to maximize survival chances. One, he had everyone stay together in the place where the accident happened. Staying in one place allows search efforts to zero in on a stationary target. It is very difficult to find a person(s) on the move. Second, he did not attempt to walk to find help. People who do that often die of exposure, when the original lost party is found because they stayed put. The person that attempts to walk out is usually the one with the fewest injuries or the greatest strength, the very person that has the ability to help the rest survive. He lit a fire and rather than try to light a large, hard to maintain, dangerous and ineffective fire he used rocks to transfer heat from a much smaller fire.
I wouldn't put much stock in CB radios in the western U.S. It would surprise me if someone in the mountains of Pershing County, Nevada could reach someone using a handheld CB. Using lower 48 states standards the terrain and distances make much of Nevada somewhat remote. Large portions of Pershing County, Nevada are remote even though Interstate 80 crosses its northern and southern boundaries. The town of Lovelock, its county seat, is 25 to 30 miles away from the Seven Trough Mountain range where the accident happened. There are mountains between the Seven Troughs and Lovelock. The town has a population of about 1800-1900 people making the likelihood of someone monitoring CB radio at the time is less than in areas with a larger population. There are zip codes in metro areas with more than 10 times the population of Pershing County.
At its closest point Interstate 80 is 26 miles away. Would it be possible to raise a passing big rig on channel 19 with a handheld? I don't think it likely that a mobile CB would do much better and if it could the rollover would likely damage a mounted antenna enough to render it useless.
There are amateur repeaters on Toulon Peak, located just northwest of Lovelock and it appears that a 2 meter 5 watt handheld could bring one of them up from some parts of the Seven Troughs mountains . There are many large areas in eastern California and Nevada where a 2m/70cm handheld won't bring up any repeater. I knew a ham that had major vehicle problems on a relatively well traveled remote road on the western boundary of Death Valley National Park (probably more than a car per day) and could not reach anyone all the way down to 10 meters. He finally was able to make a packet contact on HF. Propagation conditions were not good enough to allow a voice contact. I only bring up this example to point out that a CB radio would be worse than useless in large parts of Nevada.
The only suggestion I would in this case is to prepare and carry a basic vehicle survival pack. Such a pack should contain the ten essentials (for foot or in a vehicle): map, compass, extra food, extra water, extra clothes, flashlight, first aid kit, knife and fire starter. The extra food and water would have given this group more of a margin for survival. Had they not been found after two nights they would have needed an extra margin to survive a third. My vehicle survival packs contain a pressurized gas backpacking stove, a full fuel canister and a small pan/pot to heat water in. Hot liquids can be a life and death survival item when hypothermia comes a knocking. If water is in short supply and snow is available the stove can be used to melt water as long as sufficient fuel is available. There are websites that list items for a 24 hour vehicle survival pack. After looking at such a list I put together one for each car and won't leave home without them. My 4WD has a 72 hour pack as 4WD's allow you to get stuck four times worse in more remote country.
I also don't leave home without a ham handheld, extra batteries and a mounted mobile. Ham radio coverage is often available in areas that don't have cell coverage. It doesn't take a huge effort to study for and pass the technician exam. Having ham equipment could save your life. I don't have my general license yet, but once I do my 4WD is going to have a HF rig. Counting on the higher bands is likely unwise. The PLB and sat phone suggestions are good. A PLB that can send a short text are the best as being able to report the circumstances of your situation helps rescue teams focus the right resources to help you.
However, even without these things this group survived because the driver made all the right decisions while doing the best he could with what he was dealt. I think most individuals would not perform as well if dealt the same cards. 'This man deserves congratulations!