You can certainly leave the swarm to build in the trap for several weeks and get established (and to give you more time to build more hives if you get very lucky). But I think 11 bars is a little bit small for overwintering - it can be done in the South, but the colony would be pinched for either space or food or both.
Best to use the swarm traps as an interim solution so that you can judge how many hives you need, then move them over into their new homes once they have brood that they won't want to leave.