I know that you should block off rooms ahead of time so that you can include the information in your invites or post to your wedding site but how do you go about figuring out how many rooms you need to block off? Much of my family is located close by and will be able to room up with other family. However, the FH family will be commuting at least 6 hours. We have offered a room at my house to his parents but other than that my family's house is full.