If you're planning to render anything with good quality, then forget about laptops. No one who is even remotely serious about creating 3D renders is using laptops. Compared to desktop PC's a laptop that is powerful enough costs a fortune and is still inferior when it comes to reliability, upgradability, using multiple graphic cards and so on.
If you actually want to buy a new laptop and in your mind you are bringing up this "excuse" as a good reason to do it, then just don't lie to yourself
If you want to get serious about 3D art, then buy a desktop PC that has enough room in its case, several large intake fans with dust filters and multiple PCIEx16 ports. Or better yet, build one yourself.