my understanding and correct me if im wrong is to put space between you and your abuser to reduce the chance of you being tracked down. so although (detail removed by Moderator) miles might seem like a long way, it should keep you a safe distance away from him.
isolation shouldn’t be a factor unless your concerned about your family and friends, and again, from a safety perspective you need to consider where he’s likely to look for you once it all takes place.
refuges have support staff and other women living there going through the same things as you, if you need company someone will be there for you to talk to,if you need time alone you are safe there too.
refuges can help you set up new housing, schools and practically a new life away from your previous one without the risk of crossing path with your abuser, personally if i lived within 5 miles of my abuser i’d be constantly anxious that id walk past him in the street or something.
at the end of the day only you can make the decision.