Baaack over here on topic, a couple of thoughts from my own experience:
Your husband’s opinion is waaay more important that your family’s. We were in a similar situation a year ago (I was the spouse on the fence, she loved it) and bought the house. The naysayers have long forgotten about their dislike, and my wife thanks me weekly. With kisses.
Regarding the baby and the moving, try to see the timing as a mixed blessing. Fixing it up and moving in will take a month, but then you may never have to move again (moving with a 3-month old won’t be any easier, and could be a lot harder). Pay an extra month of rent at your current place to lower the stress. Enlist friends and family (who are usually looking for ways to help the new mother) to lift and paint. Get your husband to agree that moving into his dream house right now will require him to use his paternity leave. Your job can be to sit in the middle of the scene and direct the volunteers, and no one will begrudge it.