Believe it or not, four o'clocks make a black tuber-like thing that you can dig and store like you would glads or dahlias. One year I tossed one on a shelf in a cool room and it grew when planted the next spring. I'm not recommending that "storage" method, but it shows how much abuse they will take! :-)

I over wintered fuschias in my attic one year. They started growing shoots in early spring. You could give the mums a try.
One year I left my mums in the ground during winter and because we had a heavy snow layer they all came up beautifully the next spring. If the snow layer isn't very deep, they don't get enough protection and they will die off.

I put the pots in the garage around Thanksgiving. Keep them well watered til then and then cut them down to about four inches. The bigger the pot, the more likely they are to sprout in about March. Then I put them outside in a protected location. It helps to divide them before planting in the ground in the spring. The majority come back this way.

I have two varieties that are fully hardy in the ground year-round with no fussing at all, and we have gotten down to -22 F. One is a beautiful coppery color (a mix of reds, oranges, and yellows close up) and very double, and the other is a single daisy-like flower, pink with a yellow center. So, maybe look around and talk to the garden centers in your area to see if there are any locally available varieties that you can just grow year-round in a half-barrel planter, an old chimney tile or in the ground.