Tate, my take on growing potatoes 'above ground' is to not waste your efforts. It's too warm here and potatoes like it cool. Bear in mind that molasses buckets are usually black so if they get any sun, the soil will be even hotter. Plus being plastic, they don't 'breathe' or drain well. Worst case scenario is the potatoes will rot... best case is they will be steamed & ready to be eaten right out of the ground.
I do use molasses buckets for peppers & fall tomatoes because they like it warm/moist. I should note that they are kept on the north side of the house to limit their exposure to full sun.
Just my 2 cents... Good luck!!!