I had a long trip with one of my dogs shipped in cargo. The airlines transport pets in a temperature and pressure-controlled cargo area, so the main stress he would be subject to is noise, confinement, and the general physiological weirdness of the flight itself. If Basil isn't used to crates, make sure he is accustomed to them NOW if you are planning on going this route. It'll make things a lot easier for all involved.
I did find it helpful to check in with flight attendants at each transfer point. I wanted to confirm that they knew where my dog was, so I could be assured that he was transferring with us. I've heard horror stories of pets that got misrouted – and this has certainly happened to me with luggage -- so I insisted on making sure, and they were usually sympathetic to my concerns.
That said, I think it's best to talk to individual airline reps on the phone if you want to get a feel for their how they do things, because it can vary by airline. Traveling during hot months can also be a problem. Some airlines have total embargoes on pets during summer months through September, and some will only ship pets contingent on the weather that day. So if it's more than 65 or 75 degrees that day, they might not let you on board at all because Basil could overheat while sitting on the tarmac waiting to get loaded into the plane.
Traveling with pets can be a bit stressful. I wish it were easier. Is a road trip out of the question?