[elhigh]

I second modding the trip.

When my kids were small and before we had a minivan, we had a Hyundai Excel.

That name was not earned.

Among its many other faults the car's AC was not very powerful but in spite of its poor output, it had a marked effect on the car's performance on hills. To compensate we changed our long trips to take place mostly in the very early morning. To take trips from E. Tennessee to visit my parents in N. Virginia, we would set out at 4:00am. That put us arriving shortly after noon, just as it was starting to get too hot. We did about four trips that way and it was always a much, much better option than starting after sunrise.

Another realization that came out of one of those trips was when we took a detour across the bottom of the state to visit Colonial Williamsburg (hi, Old Mech!). Proceeding up I-95 was a nailbiting nightmare until I backed the cruise control just a couple of miles per hour slower than the vast majority of everything else. Then it became quite a relaxed trip and everyone simply flowed around me.

So: traveling earlier means less AC (and less traffic); slowing down, besides its other benefits noted in these pages, means less stress.