Personally, I don't think it is right to take her way from her dad for an extended period of time. Especially if he wants to be in her life. It is unfair to him and her. You new DH is not a replacement for the real thing. I think you have one of two options:
1. Stay behind in Co. while you DH works in Tx, for you daughter to be able to habe both her parents. Think of it as a deployment.
2. Leave you daughter hear with her dad, since he is not the one trying to move to another state. If you would rather be with you new DH then have you daughter with her daddy, then you can leave, but it's not fair to rip her away from her dad for your own reasons.
I like the idea of her coming with you for the summer and back with pa for the school year, that is a GOOD solution for this problem. And it is fair for both parents involved and also keeps stability for your daughter.
When the move is permanent, you have some tough choices to make. Your DH might have to not take the job, or you'll have to leave the baby girl. With blended families (I am a child of one) things like this come up, but the important thing is to keep the best interest of the child in mind. Not what you want, or what is most convenient for the adults, or even what makes you happy. You daughter needs her dad closer than hundreds of miles away.
As for the court penalizing you for moving, that is very possible. With my parents divorce decree they could live no more than 30 miles away from eachother, or else the parent that did not violate the dicree gor full custody until the other party came back. You will have to check with your lawyer.