I think I would keep them only until I find a full time client, you've waited so long and then they keep asking for more flexibility and I won't be surprised that something else happen before January. I know it is getting hard for all of us filling our spots and I'm also certain that it won't get any better but, do your very best to advertise and offer your spots. Hopefully you can fill them up in no time. And you do not have to keep waiting for a family that might or might not commit 100% causing you to incurr in financial loss.