So...succulents in the ground, in the Midwest? Yes! You just need to choose the correct ones.
Not my picture. These are Sempervivums, hardy to -20 F
Webpage for picture can be seen here: Simply Succulents
I have not ordered from this website, but you get the idea of the colors available! I see they are in zone 3 in northwest Wisconsin, so I will definitely be looking at their website some more.
More borrowed pictures. These are Sedums, also zone 5 hardy, and some colder, all the way to zone 3. Assorted ground cover Sedums in a riot of colors (also called stonecrop)
The taller type that blooms in the fall
The pictures are from Mountain Crest Gardens. I have not ordered from them.
There are other types of cold-hardy succulents. You can do a Google search or visit the websites above for more pictures and info.