Will the judge allow relocation of custodial parent if other parent and both sets of grandparents are active in the children's lives?

My recently divorced daughter is planning to remarry shortly and wants to move 600 miles away with her children. She plans on going through the court to see if she can do this. Her ex husband is not going to permit this and will file the necessary paperwork to not let this happen. There are no extended family or friends of my daughter there to help her other than her new husband. As a worried grandparent, what is your opinion? I'm just worried sick they will let her take the kids. Her ex husband is very involved with the kids as both sets of grandparents.