If theres one thing I've learned from polyamory, and relationships in general, its that things don't usually go as planned. I understand your desires, when I started out I wanted nothing more than a big family of people, all loving one another (even if not physically involved) and all living in the same house and caring for each other. I'm lucky now to have the two wonderful partners that I do, and have seen my dream come true. It really wasn't that simple though. I've been with my fiance the whole time, but many other partners have come and gone. Many people who I've been close to, were not people my fiance got close to or opened up to. I am very lucky in my second partner. I would never have expected Lady and my fiance to become the dear friends they are, or for us to have become such a closely bonded family, but it did happen. I learned many times along the way that you can't force things. People are unpredictable, with very varied and vast needs and desires, and those you love may not have the same desires as you. Those who have the same desires, may not be the people you end up getting close to. And above all, people are ever changing and growing beings, and just because your love and desires for a certain lifestyle match up for a time, doesn't mean they always will.
I would strongly advise that you focus not on your eventual goal of a household of women, but on meeting individuals and growing close to them. I found that when I focused on just building healthy relationships, that the rest fell into place in time. Also, you need to realize that these are individuals. They may like some of what you want, but not other parts. They will possibly want to date each other or other people outside of the household. In time you might find that you want that as well, even if you may not feel that way now. They may want to be the ones who help take care of you, not just be taken care of. Some may not want children, or may already have children. Think all this through and take it into account. Are you willing to develop healthy relationships and give these hypothetical women the freedom to grow and love in the ways they choose, even if it may not fall in line with your plan? Can you compromise and give up some things for them, or change and negotiate with them? Because you will almost certainly have to if you want to make this work for you. You need honest and open communication, and the ability to compromise and work with a partner, not just be in charge and "take care of them". Can you do all that?
Also, as far as you soon to be wife, talk to her. Talk frankly about what you want and how important it is to you, and why it is so important. If she does not want the same things, either one or both of you need to compromise and change, or you should end things. Its hard, I know, but its better than you both trying to force yourselves into a relationship that can't satisfy either of your needs and goals in life.
I do hope you eventually find happiness and reach your goals and dreams.