There are some cold region succulents that can withstand colder temperatures like Sempervivums and stonecrop sedums!
Succulents shouldn't be confused with plants that are “succulent-like” (examples, Snake plants, Hoyas) who do have fleshier, plump leaves. While they may appear to have the same characteristic which helps them become more drought tolerant the plant tissue is not the same as the ones Succulents produce.