Vincas are full sun look-alikes of Impatiens and come in several colors and are great for hanging baskets and urns. That is what we used a lot of in our full sun home in Mobile. Also, there is a variety of flowing Petunias that look great in urns and hanging baskets, but I am not sure if red is availible, my wife always favors purples!
I’m not familiar with the vincas whereof you speak! Vincas I know are a ground cover with little purple flowers, or a green and white vine that we use as “filler” in combined pots. When that stuff escapes the pot, you can never get rid of it. It is definitely “cold hardy”.
In New Jersey, I discovered vinca...not the vine with purple flowers (sometimes labeled periwinkle) that people use for ground cover or the variegated vine people use as filler in pots, but an annual. It looks very much like impatiens, but can take full sun and is very tolerant of heat. They come in all sorts of colors. They don't mound like impatiens, but grow a bit more upright. They fill out and make a huge plant covered with flowers by the end of the summer and do not need to be pinched back. Pretty much the perfect plant for a lazy gardener! I can't ever find vinca in a big garden center, but a mom and pop place here grows them every year. He tells me that they are tricky to germinate and prone to root rot if you overwater and that is why Lowe's , etc. doesn't fool with them. He doesn't have them ready to sell until beginning of June, so I always talk him into selling me some in May before they have flowered. I never know what color I am going to get! Usually pinks, coral, white, and lavender are the most common colors. It does come in white with a red center and a gorgeous solid red, but those are few and far between. If I get them in the ground around Mother's Day with some Miracle Grow time release in the planting soil, they look fabulous by July and pretty up until the first frost. They are my go-to plant for full or afternoon sun.I have never heard of this plant! This must be the sme one that you recommended. m going to have to look it up. They must call it something else around here.