Even if a mini did spread for you, 2 ft is pretty good sized and they don't root very deeply so just digging some out every 3-4 years would be the easiest way to go. You can sell or give it away. I have had several minis and they didn't thrive well for me. I find they are too puny to make our winters here for one thing. Since they are little and have shallow root systems they tend to heave out of the ground in the winter and die.
You may also consider astibile or heuchera for a shady area of that size. Or woodland phlox. None of these are have a winter presence much, but neither do hosta. Actually my woodland phlox stayed green over the winter this year. ( I probably spelled those wrong! )
