The e-GPU would be a much better option. MacBook Pro 15 with External RTX 2080, assuming this laptop has support for Thunderbolt 3 port/interface.
The MAX-Q variant would be slightly dialed down revision of the original chip. A power saving variant more like. Though, it is based on the same TU104 chip in the desktop and mobile variant and offers 2,944 shaders, and 8 GB GDDR6 memory connected by a 256 bit interface (12 GHz).