I need some honest advise on if we should drive 6 hours to get a dog at a shelter?

Me and my husband have a 20 month old son and a cat. We are renting (no lease, pets accepted) a 2 bedroom house in town with a good sized back yard with a chain link fence. We put in an adoption application for an American Eskimo/Collie mix and got accepted. She got spayed last Monday since we are adopting her this Saturday. It is a 6 1/2 hour drive to this no-kill shelter. It's a nice facility and have certain rules for adopting an animal. I mean, we have never drove this far and neither of us are very good at driving through the city and we have to go through it. What if we get there and this dog is nippy, doesn't like us, or has some other problem? There are so many things that can go wrong. What do you think? I drive a Taurus so I'm not sure how the puppy will do with that either.