That would make a really good brooder. Take out the nest box dividers and add a heating plate in a corner of it and now they have a perfect dark, warm corner to retreat to and lots of room to playOn a more serious note though . . . that henhouse (https://www.amazon.com/dp/B0DRJCDQDN?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_8&th=1) would make a great outdoor brooder.
I just need to remove the solid doors and add hardware cloth (screen doors) for better ventilation. I could run an extension cord from my bedroom window for a brooder plate or two and I'd be back in business.
When the girls were only laying eggs in it I just left both doors and Daisy, my dog, never bothered them.