Not a lot of laptops can do GPU pass-through. Most laptops that have both internal graphics and GPU have both display devices hard-wired to the same outputs, and they can’t be used at the same time.
You can look for a laptop with optimus hardware, as far as I know it’s your only option if you want to do GPU pass-through on a laptop. Even if you find a laptop that is physically able to do pass-through, it also needs to be supported by qubes.
Once you have checked all the boxes, you end up with a short list.
Even if you get it working, you would still need to carry around a second monitor to do the GPU pass-through.