Wife Wants Chickens

What this really means is that she likes the idea of having chickens and not actually investing the time it would take to raise chickens. So I’d be the one doing all the work. If I do this I’d like to do a combination of free range and a run. I leave for work early some days, before sun up. My question is how big of a run is needed for say 8 chickens? My plan would be to let them free range the mornings I don’t leave early for work and let them stay in the run when I do. Of course I’d have to figure out a water and feed process but wanted to know if that was a sustainable plan?