I worked at a big centre so I know that they try to toilet train really fast when the child starts and they have the other kids to act as role models for the younger and new kids so don't feel like a failure as the same thing happens when the children leave me but it does not bother me at all LOL

The parents seem to have tried to stay with you for as long as possible and now they now you will close mid-Feb they have to look for a new daycare and it just happened now rather than later, it might be worth while to close earlier as less income will effect your EI so go for it