If I were in this situation this is what I would do.

To right a boat, you need to point it atleast 45 degrees into the wind to make the task easier. If I were to help someone, I would aproach the capsized cat from the rear, tie a line to the capsized boat so mine does not drift away, release all my sails, pop the rudders into the up position, and help the other person right his.

But I think if wind is blowing 20kts, I would not be sailing alone. Remember to use common sense, if you think it is unsafe, then it WILL be unsafe.