How long would this work

My boyfriend and I went out and bought this deep freezer so I can store my milk for a longer time than just our freezer. I was so excited thinking I could store milk for up to a year now but my friend who helped us move it over to our house told me since we only got a small deep freezer I can only freeze the milk for up to 6 month. 😔 We have a small house so we couldn’t get a real big one and I though any deep freezer, no matter the size, you could keep milk in it for up to a year.? Is she right? Also what is a good setting to have to store milk at? It goes from 1-7. One being the warmest.