One person on this site at one time, had a trailer that could handle a dozen dogs in built in crates.
My malamutes did not like riding in the bed on a 100+f day, put crates in trailer, they hopped in. Same on a below freezing trip from Sand Point Idaho.
As I said earlier, your mileage may vary on where is best for the dog(s) you have. Not sure my two King Charles Cavalier's would be happy in a crate in the trailer. But the malamutes by their own behavior let me know where they wanted to be.
As far as humans go....a y of the crew cab pickups will work. All three have plus and minuses.
Marty