Best way to make a walkthrough video from 3DS Max file?

Hey guys, I'm doing a 3D model and walkthrough video for an architectural company. The model is massive.

It's an 18-floor residential building comprising 9M polys and growing. (including furniture, decorations, plants... Yes, I will optimize it before I'm finished, but still, it will be huge.)

Is there any way to create the walkthrough video in Unity? I love Unity and would like to use it to create this video if possible.

But I'm worried the fps will be abysmal. Is it better to make the video in 3DS Max?

Any suggestions or workarounds from you seasoned veterans would help!