The best tip is the inform the LFS at the time of sale about the journey time.
Normal bagging with air in a tall bag is fine for about 3-4 hours. If you are going longer than that, you need to pack with oxygen. This is how some fish survive transit as long as MW states. Normal air will not allow that kind of survival time
Polly box them, but I would not try to temperature regulate... Heat packs and in-car heating can overheat the livestock, so they are best left "too cold" this time of year during a long journey. When you get home, take about 10mins over actually un-packing them. Suddenly introducing them to light will potentialy photo-shock them and possibly give them temerary blindness
When you get home, dim the lighting in the room. Switch off the tank lights. Open the box, and leave the lid ajar, such that it is not all the way off. Leave them thus for 5mins before fully removing the lid. Again, leave 5 mins and then lift SLOWLY from the box. Now float them
With this length of time, pH will have dipped slightly due to the presance of CO2, and ammonia in the bag will be raised. The low pH will keep the ammonia as mainly ammonium, so do not airate the bag, or you will make the water more toxic, just float them in the SEALED bag for 20mins
You are traveling a fair didtance, so water conditions will be different. As a result, you either need to add a cup of water every 10 mins untill the bag is full, or drip aclimate with an airline and bucket to avoid any sudden changes to the water conditions, that could shock the fish or even kill them
All the best
Rabbut