Given those temps, I would still use a heat pack.

And proper Lacey Act labeling is important, even for short distances. Not sure what method you are using, but if you are not individually FedEx certified to ship live reptiles, use the ShipYourReptiles.com service, so that you are covered under our certification. Shipping without a certified account is dangerous for the animal, and bad for the entire hobby.

Sounds like you are on the right track, best of luck!