Keep the plants in a protected spot, i.e., out of direct winds, or low spots where cold air settles, and you should be able to get a few to winter-over. I keep tender plants near concrete walls and patios that absorb heat during the day and keep surrounding areas warmer at night than open yard. Good luck.

Sink the pots in the ground and they will be fine. I mow these in the lawn and in spring the little 1 inch stems always sport new leaves. At that point I dig them and offer them up for Bonsai :-)