Keep food cold and safe?

Cool the items you've made first in the fridge.Use an insulated chill chest and fill it with some ice or those plastic freezey things.Load the food and maybe use bunched up plastic bags to build some support around the items to prevent shifting.Cover the items with some plastic too to hold in the cold.Should be fine for 6 hrs. imo.

cooler for the pie and whipped cream.

AND chill the soup and use a cooler for that too and heat it when you get there.

You need an Eski [cool box], there are lots on the market.

Theres even a powered one you can plug in on the dashboard [lighter socket].

Good for both items when stored correctly.

Surely they have grocery stores and deserts where you are going.

Put them in a cooler with a couple ice packs.

?????

Don't put the whipped cream on the pie until you get to the destination so it doesn't get all messed up in the cooler. Just whip the cream and put it in a separate container inside the cooler.

If you really want to be clever, you could freeze the chicken soup and that can keep the cooler/pie/cream cold. It may not thaw in three hours though.

Buy storage containers.

Keep food in shade.