I can't even remember the full list of all my "all season" crap, and there's probably stuff that I could improve on the Winter side, but most of my stuff is in a small ruck with all the basic "get home" stuff - Coast Guard rations, bottled water (also bottles in various door nooks), water purification, fire, IFAK, emergency bivy and blankets, spare socks, wool cap, TP, big trash bags, flashlight (also multiple flashlights in vehicle and my pocket). Anyway, that stuff and a bunch of other stuff.
Otherwise, Winter specific, a sleeping bag, gloves, and boots. In the Winter (and most of the Summer) I actually wear boots anyway, but in the 4Runner I also keep an old pair of Oakleys just for "keep the feet dry" emergencies. jumper cables and jumper battery, a couple of those plastic folding "traction tracks" (probably not good for more than one or two uses, but that's likely all you need). Kitty litter in the 4Runner, a couple of ($4 a pop at the farm store) 70lb tubes of sand in the truck. A small, I guess they call them "forester's shovels". I used to keep one of the expensive tacticool folding entrenching tools in the vehicle, then I decided to actually test it, and man, those folding handles are crap. You're likely to need your IFAK before you're done digging with it.
Speaking of IFAKs, I started using one of these to keep my vehicle IFAK (separate from the ruck IFAK) and stop the bleed kit, and several other things, quickly handy via velcro:
https://www.amazon.com/dp/B07KTL87PXI'm sure there's stuff I could improve on, but I know what I have will keep me alive and relatively comfortable until help arrives. Which, I can't wait until Elon makes Starlink phones. I find myself in a lot of "no cell signal" areas, but would feel a little foolish activating a personal EPIRB to call for help.