Family expectations

So my husband and I are expecting our first baby and alcoholism runs in both of our families. It’s predominantly on my dads side and i very rarely see that family. It’s a little more evident in his family though, and we both don’t feel comfortable with having people drink in excess around our child. I mean a drink or two is one thing but drinking to the point of throwing up or stumbling around just isn’t something we want our child to see. I’m totally prepared to tell my family how i feel and deal with the backlash but I’m nervous about how my husbands family will respond. Any advice?

Also, we want to talk to them because we want our kids to have a relationship with their grandparents and aunts and uncles instead of just keeping them away without any explanation