Grammar help

[Pennies]

Which is correct...

The Smith family are having a party. Should the invite read...

a) Party at the Smith's

or

b) Party at the Smiths'

or

c) Party at the Smiths

Their family name is Smith, they are the Smiths, therefore it should be b) Party at the Smiths' because it is "at the Smiths' House". Isn't it?

Otherwise you could say:
Party at the Smith house?

Yes, either "party at the Smiths' house" or "party at the Smith house".

Message withdrawn

Louise Smith invites you to her party

or "Chez Chateau Smith"

Pretentious, moi?