Ratchet-strapping the tent and chairs on the roof luggage rails looks like it would free up a lot of space. A thing I did to save space was go with those collapsible camping chairs like the Helinox style. The name brand are nice but expensive, and Costco sells knockoffs that are much cheaper and get the job done, but they aren’t as steady. There is definitely a difference, but go test out the Helinox at your local REI to see if the extra premium is worth it to you. I actually got the idea of using the collapsible chairs from MandATaco as he camped with 3 kids in car seats out of his 3rd gen.

Also, one of the best camping high chairs I’ve ever seen was by EvenFlo but they don’t make it anymore. They go for a crazy amount on eBay though, sometimes $350! Evenflo Babygo Travel Highchair Green | eBay

I have a green one that I can sell you for a better price if you’re near Vegas 😉