What to do if I recently found out my ex-wife would be moving further away, making the commute for me much more lengthy and costly?

First, you need to see what the terms of your custody agreement provide (assuming that you have one). If this issue is not adressed in it or if there is no such agreement, then you will need to obtain a court order directing just how far your ex can move with your child.

Typically, a judge will consider such factors as how will the move effect the frequency and length of visits, will the move effect the child's education, continuingmedical treatments (if any) and/or their relationship with the non-custodial parent and other family members, etc. Finally, the the reason for the move will be considered. If it is merely to get away from the non-custodial parent that will be frowned upon by the court; if it is for a job transfer or for the custodial parent to take care of an ill family member, then the court will be more inclined to allow the move.

At this point, you need to consult with a family law attorney. 

I suggest that you carefully read the presumed child custody agreement to see if there is anything within it or in a child custody order preventing your "ex" from unilaterally moving with your child without your or the court's approval.

Once you get this information in hand, you need to consult with a family law attorney to see if your "ex" can do what she desires to do absent your or the court's approval and from there, plan your course of action.