Need recommendations for laptops

Im looking to purchase a laptop under $3000 Needs: -To capably playback 8k mp4 files (when unplugged) -15 inch screen or smaller

Wants: -4k screen -32gb ram -UHS-II sd card slot -Thinner & lighter the better

I have a workstation at home that I use to edit videos but after I recently upgraded my camera setup I can pretty much not view files until I’m home. I purchased a razer stealth with a 1660 ti and it couldn’t play back video smoothly so I got rid of it and now I’m in the market again.

Anyone with experience with x9 carbons, T14, P15 etc that can let me know how they power/thermal throttle when unplugged. I don’t want to waste time buying another laptop that cant do what I need.

Thanks!