@iKirin Ah I see. An iteration of both.
@Xify Smaller Form Factors would be ideal. Those cards used in HTPCs and such. Akitio Thunder would be an ideal model. Very Barebones would be a V8.0 EXP GDC. Just add an enclosure, power brick, and change the MiniPCIE to thunderbolt, then you have a winner.
Getting ahead would be a barebones card (such as those seen on water-cooled models), with an adaptable yet thin profile solution of cooling (water cooling or thin profile coolers). Maybe a barebones reference card with a designated/universal layout and a thin profile cooler that works to cool every component of the card as needed; which will cover the chip/GPU, memory, VRM, and anything else that needs to be cooled.
There are three means of cooling for a desktop GPU
1. Air (Heatsink & Fan)
2. Liquid Cooling (WaterBlock + tube on GPU. Tubes will connect externally to a radiator+Fans, and a water pump)
3. Hybrid (Essentially the same as liquid, in an already tested closed system; no need for maintenance)
I haven't seen many thin-profile heatsinks + high pressure fans (Air method) on higher end GPUs. Maybe they just don't provide adequate of efficient cooling as their two slot counterparts?
Then there is liquid cooling, which is slightly smaller in width but ends up taking up 2 slots anyways. Going liquid offers the best cooling, but it comes with a price of the pump, solution, radiator, heatsink (none of which is cheap) and would require maintenance.
Most hybrid solutions are just as bulky/same size as the normal fan+heatsink options. Hybrids don't require maintenance, so there just needs to be an area to mount the radiator. More cost-effective and less work than traditional liquid cooling.
I think no matter what if you are going the high end desktop eGPU route you will need at least two slots of space. So it will be a slightly less long, bulky box, haha?
If those with an Eve V just want to game periodically, GeForce announced their NOW program at CES 2017, allowing you to stream games and gameplay into your less powerful GPU sourced computer and play off-site. However with implementation of data caps (~ United States' Comcast for example), and the charge of $25USD for 20 hours of gameplay; I am not sure who would go for this. Those who use CUDA or OpenCL for extra processing would be left in the dark.
The Cloud is powerful.
I did some research on the deGPU of the Surface Book. It isn't very powerful with a TDP of around 33W and estimated performance which is slightly less than a 940m. A desktop 950 GT would require 90W of power (as a low end/budget friendly desktop graphics card). A 980m GTX would have a TDP of around 122W. The Mobile/desktop 1080 GTX would need 180W. If you would go for the higher end models, a bulky enclosure would definitely help in cooling, and additional power will definitely be needed.
All this will lead to big & bulky. Only way to keep things cool and to avoid sucking out all the power from the EVE V.
Less bulky will definitely mean sacrificing performance, and going down to perhaps a 1050 Ti which has a 75w TDP.
MSI has created a low-profile adaption of 1050 Ti, see below.