Can anyone recommend a laptop that will run Mistika really well? I need a machine that ideally has an Nvidia 1080Ti and an AMD Ryzen Threadripper, or something very close to that, for processing in the field.

With an Nvidia 1080 Ti you will have a really good performance. Mistika VR uses mostly the GPU, CPU is used to decode compress formats and render, and the Ryzen is more than enough for this situation. If you can find a laptop with this hardware, Mistika VR will work perfectly fine.