When you consider that convicted murderers serving prison terms are able to petition for and be granted visitation in prison it isn't really too shocking that someone of your ex's character would also be successful. But don't lose sight of the fact that as of now all he is granted is visitation - not custody. As you have been the custodial parent for a period of time the moving of custody now is less likely - additionally, the fact that he is facing charges that could well incarcerate him it is unlikely that the courts would order anything beyond the visitation already granted until that is resolved and they can see if he will even be able to have custody (not a lot of room to keep your kids in a 6X6....). So, if anything you are likely to see the temp order last until his legal cases are resolved so that the court can look at his "living arrangements".
As you have the "best attorney in town", though, I can't help but wonder why you are asking us instead of consulting your attorney - his advice is bound to differ as he is more familiar not only with your state statutes but also with the mood/attitude of local family court about issues such as this - and when it comes down to it within the law there is a certain amount of latitude that the judge enjoys to "adjust" according to their personal opinions. I would suggest you pick up your phone and ask you attorney about the possibility of petitioning the court for permission to make the move - BUT it is unlikely to be considered until you have a provable "improvement of lifestyle" (ie already have a set job to go to that will substantially improve your life and that of your child if you are allowed to move) so likely won't file until you have the job locked on.
As I said, your best bet at this point is to continue working with your attorney as if you don't you will only receive conflicting advice based on the fact that we here are not as familiar with the details of your case as your own attorney hopefully is....
Good luck and God Bless
PS...just to let you know, though, in my case I was able to make a 3000 mile move with my child (I have always been CP - she is 4 1/2) after notifying the NCP (he lived 500 miles away anyway so that was a little different in our case and was to my advantage) 30 days in advance in writing -- he then had that 30 days to file a petition w/the courts to stop me but chose not to. He had that right as the move obviously has changed his visitation (not that he used them anyway - again different in my case and so may not apply for you) but opted not to fight it so you never know.....