Borrow a medium sized dog crate and have Ginny follow in a different car OR borrow a king cab truck and a dog crate to move the Ig. Don't let the Ig loose in the truck. Let him ride IN the vehicle! A leash of sorts won't protect you from teeth and claws...The ride alone will freak him half to death. The crate will keep him more secure. Make sure the Air conditioning isn't on (or on too cold) for him, and the window drafts are not hitting him straight on. In other words, its gonna be a long hot ride for you guys but the Ig will love it! I put a blanket over the crate so he can't see out too. If all else fails and you can't get a dog crate then use a box with air holes and tape it shut.
I bought a dog crate just to move the Ig so I can take her to the vet....works like a charm for me
Good Luck!
Jem