I always overpack on trips. But I've learned a few tricks to help if things go south . . .

I once saw a tow truck driver change a flat in about 4 minutes. He used a rechargeable DeWalt 18v impact wrench. (Note, NOT an impact driver which has a hammer action) He'd used a scissors jack with a hex bolt, the wrench pushed the car up in about 10 seconds, the lug nuts didn't take more than 20 seconds. The new tire was on and tightened pretty quick.

so I bought a used DeWalt 18v impact wrench, I keep an inverter in my car and found a scissors jack that was the same size as my lugs on my truck.

A "jump start" kit. It's basically a sealed motorcycle battery. My kit, bought at Costco, has a rudimentary air compressor (works for air mattresses too) and a 12v and 110v output option.

I switched to an Optima AGM type battery too. I've shaken a battery once too often when I'm driving ON the road and had it fail due to internal shorts, the AGM (absorbed glass mat) type batteries are very very sturdy in this regard, they can also be fully discharged without risking killing the battery (deep cycle I think people call it). In our harsh weather having a battery fail after two years is just nuts (and common). Generally the AGM batteries last from 5 to 10 years, mine is at 6.

If you're going to have a chain to pull things out, have a tow strap also. A chain is great, but it has no "give" and you can damage your vehicle if you use it exclusively to pull yourself or others out.

I never, ever use the spare tires that are the space saver kind. Go down to your wrecker and buy a spare rim and tire. A full size spare is essential. The space saver spare is like putting a patch on a condom, sure it works in THEORY, but when your life is at stake!

I try to carry two spare tires on long trips, but I have a bumper mount for a spare and a front bumper mount for the second one.