Oh, I missed that answer, sorry...

Yes, it is similar, but different. Offgrid is you have you solitude and nomad you are in the middle of millions of people in big cities around the world.
Did you know, before I became a nomad, I were looking into many alternatives. One of them was Van Life, another a sailboat and sailing the world. There was also getting a donkey and hiking in the worlds nature and there was the idea to go to canada and go offgrid. Each one came out to be very difficult or expensive. So I went for the nomadic way of life.
There was once even the idea to get a sled, huskies and go north. from there to go always east over russia, alaska and canada.