Put another pot adjacent and train the runners onto the dirt. They'll root themselves right quick. The young runners kinda need nutrition from mum and dad for a bit, but once their roots strike and they establish themselves you can give the parents the snip.
Just keep in mind the more runners you have going off a plant, the smaller the strawberries will be. Those runners are using up a lot of energy! If your plants are flowering prolifically due to a good season, cull the majority of the runners until after your fruit is ripe.