At the moment, there's still some uncertainty about mobile GPUs being able to run Optix / the AI denoisier - for example, my laptop has a 960M, which is based on the Kepler architecture so should in theory work; however all it does is crash, even on the simplest scenes. So for using the NVIDIA denoiser on a laptop, you'd really have to test it out first.
(as a note, this laptop is the one I use for demos at events, and IR etc is manageable without the AI Denoiser - not a patch on a desktop of course, but still manageable for on-the-go portability; it's a Lenovo Y700 touch, and except for some wonkiness with the hard drive which seems to have got 6 times slower over the last year, it works ok as a portable demo machine; I'm going to try replacing the HD with an SSD and see if that fixes it, we'll see!)