There is no clear cut answer to your question. But there are clearly WRONG answers and Suzanne P provided a wrong answer. I typically like to see what everyone else is saying before I respond but I couldn't even read her whole response, let alone anyone else's.
There are a lot of variables to consider in answering your question or offering advice. But I think I am going to keep my answer as simple and as general as possible and hope that you can make it apply to you.
The inner workings of a marriage are very complicated, but the general needs of men and women are pretty straightforward.
Women need to be loved and men need to be respected.
Unfortunately, we can tend to get into a vicious cycle where if women don't feel loved, they don't respect and if men don't feel respected, they don't love. That "crazy cycle" can destroy a couple. So my advice to you is to respect your husband in however you think that may apply. I've always believed that men are the head of the household and that women are the heart. It takes both of those to make a marriage work. However, there is a natural instinct in men to be the provider and protector of his family. They need to feel that they are doing that in order to feel accomplished and respected. It definitely takes both of your input to make a decision that effects the whole family, but ultimately, the final choice needs to be your husband's. That is his God given role...whether you believe in God or not. And that is the mantel you gave him when you vowed to "love honor & respect" him until death do you part.
Sacramento is a crazy market. People are upside down in their houses and the construction industry is taking a serious hit. The only thing that could be worse for your family would be if you were a real estate agent. I understand that this is so much easier said than done, but let your hubby do what he needs to do and trust that he is doing what he believes is in the best interest of his family. If that is ultimately to move, well, you can always move back if it doesn't work out.
You asked how to handle such a huge life change. My answer is:
Defer to your husband. Give your input and then step aside and let him make the final decision. And make sure he knows you are supporting him every step of the way. It may seem like you are being the submissive little wife, but trust me...they pay off will be huge!!