For me the definition of Polyamoury is the answer to your question. Many Loves. Love being the operative word here. If we (we are a couple again) find one more person and fall in love then we become a V or triad depending on orientation(?). If by some miracle we found another person that we all loved then a quad, if another couple then a quint(?). lol
And on it goes. Our ideal depends on how fortunate we are to find other Poly people that we are also lucky enough to care deeply about and it is reciprocated by them. That in itself is a minor miracle.
So long answer longer, our ideal would end up being wherever our hearts take us.