Adding Guests to Count - CiviEvent
with Price Sets you can add a field that is an integer that you can set so that those people are counted as 'attendees' for the sake of counting the number of registrations. You should find some helpful instructions here but I am not seeing images currently. 

You should then be able to use either the front or back end to make a registration for the 'head of household' and then e.g. put 6 in that price set field to have that registration be counted as having 6 attendees.

That may go some way to what you need.