Multiple Save the Dates to one Household with Older Children or not needed?

Etiquette would dictate that the adult children get their own save the dates, but I think this is a know your crowd thing. My family wouldn't care at all.

We sent multiple save the dates to some households. We did it because everyone had to travel to our wedding and we wanted it to be clear on who was invited so some older cousins knew they could bring a significant other or date.

We sent one save the date & one invite to each household. If a child lived with their parents, they didn't get a plus one (none of the adults that still lived at home had girlfriends or wives anyway). I know that's not traditional but it seemed like a waste of paper and stamps.

We sent one save the date and addressed it Smith Family. But then sent individual invites.
The only one we sent 2 to was my ILs house because Hs aunt lives there too and doesn't share a last name and I think she would have been slightly offended to not get her own. But they have 5 invites coming to the house, they didnt need 5 magnets!

We mailed one save the date to each household addressed to the whole family.

If they're living with parents, I'd just send one Save the Date per household!

We mailed separate invites to clearly address who was invited (or was allowed to bring a guest).

Do not include adult children on parent's save. It you do not want to spend more on Saves, send these grown kids advance info by email or text. It is more about respecting their dignity, finally an adult, not being considered a dependent of parents, issue.