We have two ways of preserving our strawberry plants:~
The first (and most successful) way.About September,lift the strawberry plants and pot them up.Cut back any runners,and trim the plant(but not too severely).Keep them in a frost free environment(but not indoors wheew they will go on growing)the following year when the threat of frost is over you can replant them in the ground.However,you do lose the chance to make new plants this way(from the runners)
The other way that does work,but you may lose some plants,is to trim them a litlle,but leave the runners on,and then cover the plants with a deep layer of straw.We haven't done this for years so I can't remember but I think it may attract slugs.Of course I can't say if slugs like strawberry plants! LOL