Best way to winterizing strawberries
Lincoln County South Dakota
You didn't mention what cultivar of strawberries you have but this information should be helpful.
After the plants have entered dormancy due to cold temperatures, and the temperatures are staying below 40°F, straw mulch should be applied about 4 to 6 inches over the top of the plants. This mulch will protect the plants from extreme winter cold so they will emerge again next spring.
Winter is the time strawberry plants will rest, so there isn't much for you to do. A good snow cover on top of the straw mulch will help insulate the plants from bitter cold temperatures, so enjoy watching that snow pile up!
After raking straw mulch off in the spring, keep the straw mulch between and under plants to help retain soil moisture, prevent weeds, and give the berries a nice clean surface on which to ripen.