Though I am not an advocate of Crating, I must admit, I have one
It's a whopper, and I can get both of my little guys in it easily.
Admittedly, IF something happens, both of mine would probably be inside my SUV, not in the Crate, but, I'd take the Crate anyway.
Primarily, I'd use it for their Suitcase, it could hold...
Papers (proof of Ownership/Pictures)
Bowls, both Water and Food
Bags of Food
Blankets/Pads
Poop Paper and Bags
Leash, Harness, Collars, Reels
Long Rope Leash's (20/30 ft for restraint in a Camping/Rest Area)
Water Containers (their supply)
Just anything/everything they would need for several days.
Then (as a lost resort) a place for them, should I be in an area
where restrictions were enforced.