Well you may not be able to get them to swap out a box magazine from a machine gun in 6 seconds, but you might be able to get them to pull a very small weapons platform? I'm thinking "1911 taped to a stick on a sled" but I'm open to brainstorming.
While you an pull the upper/lower apart, idk if I'd consider that "cat carrier size" unless you have an SBR.
My rifle would need to have the barrel and stock pulled off. Definitely need some sort of takedown rifle, but most mass produced ones are crap. I used to sell guns at a previous job, and we usually didn't get high end stuff unless it was a special order.
I think by the time you "NEED" a rifle in an end-of-world/society scenario, most of humanity is probably dead, the nuclear fallout has mostly dissipated, and you now need one to assist in hunting/scouting. Until then, I'd wager you're right about one not being necessary. Shorter barrels, less weight, you really aren't going to be engaging with anyone beyond 200yds even in large urban settings.
Honestly, I confident enough with my 9mm and my 45 that I could see myself just grabbing those with my utility bag and 4 day kit, and leaving all the heavy ass rifles at home. The only exception is if there's enough time for my wife and I to grab another round of stuff after corralling the dogs.
As for needing the rifles during civil unrest, well... I have a few neighbors who are definitely going to be ICE targets soon, and they have been invited to start shooting with us in preparation.
I miss the good old days when target practice was fun and banter was abound, now things are too far gone for any sort of levity in those situations. We all know why we are practicing, and will likely need the skills to be as polished as possible soon.
If Obama did it, I'm positive we would have sitting congressional members calling for his execution for treason publicly.