Small ceremony-Big reception?

That would be very rude. The reception, by definition, is the party the newly married couple throws for their friends and family to thank them for coming to their wedding. Inviting people to your reception who haven't even seen you get married is just going to come across as a blatant gift-grab. If you choose to have a small ceremony with only a few people, you are automatically choosing to have a small reception with just those people. If you want to celebrate with 100+ people, you better find a new venue to get married in that will hold all of them.