Oh No!!! What should I do!?!?!?

My daughter's father has to serve six months. His parents currently live about 10mins away from my house. His parents will soon be moving to another town that is six hours away. They want to be able to take my daughter with them for two weeks and then bring her back. I can hardly handle her being at her dad's for a few days and then there are other things to consider. My insurance only covers the county I live in, my daughters doctor is here,, what if something happens?!?!? I don't know what to do I don't want to tell his parents they can't see her because of how far they are moving but that isn't fair to tell them they can't see thier granddaughter? Would I be wrong or mean if I told them I don't think it is a good idea?