I pick mine up in the back of my vehicle. I'm only 30 mins from the abattoir, and the meat's been in the fridge, so it's still cold when I get home. If I had a longer journey I would cover it with polythene and put some frozen bottles of water in with it.
To suggest it go in a refrigerated vehicle sounds very impracticable for the average person, and I would have thought totally unnecessary anyway.
I see your abattoir have only "advised " you, as obviously, as a commercial concern, that's how they would have to deliver it. But as a private individual, for own consumption, it must be up to you.