I need to drive 20 miles on the highway home, is this tire safe to to do that or is the wire a serious concern? I've driven 10 miles on it so far.
Let me preface this by you do any of this at your own (and passenger's if any) risk. That said, you should be able to drive this the extra 20 miles to get it home. I would drive slowly (back roads, 35mph maximum) if possible. The idea with that is to keep heat in the tire down to a minimum. Also, if it does blow out, you should be able to keep the car under control while you pull it over to the side. I have seen tires in worse shape make it further, but no two tires are the same.
There are two things to think about with your tire here. First, what caused the tire to wear unevenly. Secondly, instead of going home, you should think about taking it to a tire shop to get it replaced. When you get it home as it is, what are you going to have to do then? Take it to a shop to get the tire replaced, but you'll have a bunch more miles on it.