Child Custody Relocation Guidelines

I moved here three years ago to fight for custody of my now 6 year old. After two and a half years and attorneys on both sides, we reached an agreement the morning before trial. I now have */* custody, visitation, and decision-making for school, medical, etc. His mother and I have always seen things very differently. I believe she is dangerous as the primary parent due to her history of violence towards me and ongoing emotional manipulation towards me and our child. She believes that I am dangerous due to her lack of accepting responsibility for her actions and generally assuming everything I do is with malicious intent. When I have our son, he is happy, well fed, well behaved, and doing well. We have started seeing a counselor monthly to help with his transition to a full time */* split, but I have not had many issues to discuss during my time. When I mentioned potentially doing this as needed only, his mother said that she was having behavioral and communication issues with him during her time. She is not regularly around him during their time, working and picking up extra shifts often and having her boyfriend/fiancé take care of him instead. Her SO has slandered me in front of me and my son, calling me a "deadbeat," among other things, so I have on numerous occasions expressed that I am not comfortable with him being around our child, knowing he is willing to disparage me directly violating our parenting plan. I have also expressed concerns of our child's confusion, because he is calling me by her SO's name and then correcting himself more than a few times each visit. Instead, she just says she doesn't like who I have around him during our time and ignores the emotional damage she's doing. However, I was notified in January that my lease would not be renewed due to the owner selling the house, and have been looking for local housing since then in an attempt to keep the parenting plan the same. I have submitted applications, called many others, and have even submitted an application through the local Housing Resource Center to show I have been committed to staying in the area, if possible. In considering "local" options, I have even considered moving to the Seattle or Spokane area and have shown willingness to concede time for him to attend school here if we retained our legal arrangements. All of those options have failed, and my most secure option for housing is moving out of state to Lexington, KY with family. If we were to make that move, he would be in a better school system and living with my aunt, a pediatrician and a second cousin younger than him who they are used to caring for, as well. What are the chances that my son would be allowed to make the move with me?