I visited the out-apiary today and opened the 3 hives there. There is evidence of brood, new comb and stores in all of them. There's evidence of a nectar flow, which isn't much of a surprise given that Oxford is swathed in spring blossoms.
Hive B is still relatively small but ticking along nicely. There are plenty of stores and reasonable coverage of brood. I haven't added space because there are empty frames in the brood area.