Yep, sounds about right. My dry girls get a sprinkling of soaked shreds with some oats strewn over it, when the others are fed, plus carrots. Other than that only hay. They'll be fine. They may make a small udder again in spring (or not, some goats do others don't),and you can then decide if you want to milk them (and increase concentrates again) or if not just leave it and check regularly for mastitis. Rich ring grass may just ring them back into milk...