I assume we are talking about specifics here, so I'll go in order of likelihood - and I'm thinking SHTF is REALLY serious, so I'm leaving out normal nasties:

1) Monster Winter Storm
2) Tornado
3) Flood
4) Nuclear power plant accident

I'm not ranking it, but an extended energy outage, such as gas, NG or electricity, would make for some pretty nasty living conditions in the winter. And it would be certainly uncomfortable in the 95 deg. F/70% humidity Illinois summers.

I'm even less concerned about any sort of attack, as there really isn't a ton of critical infrastructure or high-value targets in my area other than the nukes.

I haven't tailored anything, other than leaning heavily toward "winter storm" scenarios to make sure we have plenty of food and water on hand in case things freeze up and we can't get to a store (or they are cleaned out due to delivery issues). For floods I should probably consider keeping some water and gear in upstairs and maybe get an inflatable boat. But where I live there hasn't been a flood in 50 years since the Army Corp of Engineers built a dam system. This year was scary though - we had some rains that pushed it to capacity... and they are 50 years old.

As for the vehicle situations, I rarely consider those "SHTF", but maybe I should rethink that for a winter scenario. I do carry quite a bit of supplies and I beef them up regularly.

I carry quite a bit EDC, including a man-bag that goes with me pretty much everywhere. And my vehicles are loaded up fairly well - but this reminds me to get some MREs for the car-packs.