We are first timers getting 3 or 4 NDs this spring! We are looking at the round polydomes for their housing but they come in two different sizes, standard 7' and the mini 6'. How many goats will each of these accommodate? I'm leaning toward just getting the standard size since it is only a foot bigger and we may in the future end up with 6 or 7 goats in our heard...thoughts? Thank you!