You are correct, you are rapidly blowing drawcalls on these seats. If the seats are individual meshes, you may use Instanced Static Meshes or Hierarchical Instanced Static Meshes. All of the meshes will have the same material and shape, but they can have a different Transform (location, rotation, and scale). You create a blueprint with an instanced static mesh component. Then you ‘add instanced’ to add another instance of that mesh to the blueprint.
Edit: I forgot to mention that the instanced static mesh will use one draw call (it will save you an enormous amount of overhead).