Creating Auditorium Seating That Doesn't Kill My Machine

I'm creating a pre-vis setup in SketchUp that I will then export to Unity of a large auditorium; cameras, projectors, the works.

There is also supposed to be seating for over 1000 people. Were I creating stills I would just create the chairs, duplicate, render, snap screenshots and be done. However, since this is supposed to be a virtual walkthrough, I'm anticipating that Unity having to render 1000+ foldable chairs in a large open auditorium (that would gain minimal benefit from occlusion culling) would drag the performance down to a whopping 3fps, if I'm lucky.

2d sprites won't work as their behavior of "rotating" to always face the camera will look weird. My thought is to create a large cube for each block of chairs and just have a repeating chair texture on each side....which will also look weird, but less weird than sprites.

Or is there a better way to convincingly have an auditorium full of foldable chairs that won't destroy my CPU/GPU when I try to run it?