Addressing Informal Stds & Invitations

So our wedding will on the more casual side. The ceremony will be in a church, but our reception will be at a botanic gardens with burgers/pulled pork sandwiches from a food truck, lawn games, and a bonfire and s'mores. No DJ, but will have a playlist going. We're telling people its dressy casual, but on the more casual side lol. I'm starting to gather addresses to send out STDs soon, and I think because our wedding will be a more casual affair I don't want to do the formal "Mr. and Mrs. Smith". I was thinking of doing John and Jane Doe, is this ok? Or way too informal? Thoughts?