Depends on the grass. Most perennial grasses are more long lived with a true dormancy each winter. If you are talking about annual grasses or tender perennials, you may get away with stalling growth and holding over the winter. Rubrum, for example, quits growing at mid-40's and suffers loss at freezing temps.

Phillip, glad you asked that question. I have juncus 'unicorn' to overwinter in a pot. I was thinking buried in the compost (cold) pile??? It's a little easier for me than digging holes to bury pot and plant in the soil.