Just thought that I would mention another option. From my personal experience, my three toed box turtles are pretty hardy. I am in no way an expert though. I think the Dalmatian Hermann tortoise and the Golden Greek tortoise are great options for you. You already made the best step possible by...
It is not a tortoise but it wouldn't hurt to look at the Three Toed Box Turtle. I have had one for over a decade and it has been a pure joy to have around. Being a native species to Missouri, I would imagine that the turtle could survive the elements fairly well given an occasional mistake...