Salt, pepper, onion and garlic aren't spices - they are staples.
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Same as hot sauce.
I cut back on salt when I was 22 y. o., so I don't like spice mixes with salt added. Since most have salt added, I just don't really ever buy them.
I'm with some others here, no way I could get by with just one spice. Back in the backpack/motorcycle/jeep days of my youth I'd carry a handful of 35mm film cannisters with spices. Salt in one, black pepper in another, Hungarian sweet paprika in a third. Another with 3/4 garlic powder 1/4 onion powder mix. Another with a sweet basil/oregano/cumin/tyme mix (90% sweet basil).
And of course, a small glass bottle of Tabasco and another of Wright's liquid smoke - weight be damned, gotta have those.
But in a camper or RV? Hog wild. I don't even know what all I've got stashed away in the camper.