You should never place people outside of actual families into households. If you think you want to combine people who aren't in an actual family into a household, you should use either a roster station in Check-Ins or a group in Groups.
Households are limited to 20 people.
Use a Roster Station
If, when checking in, you receive a "time out" error, it's likely because the person you're checking in is in a large household.
Instead of using a household to check in groups of people, we recommend using a Roster Station to check in people who could be grouped together since Roster Stations list everyone who has attended an event in the last 1-6 sessions, depending on your settings.
If using a Roster Station doesn't seem like it will work for your situation, you could enter check-ins on the Admin side of the event. Choose the location and enter the names of those you're checking in. Labels will not print, but each person will be added to the event in the location you chose.