I don't think the dgpu is going to benefit you for steam in-home streaming from another device. I stream from my beefy gaming rig to my MacBook Air 2011 and it seems to work just fine (though a better wireless connection could help me a bit). This is a core i5 1.7 GHz from years back.
I boil down your entire post to one question: can I stream heroes of the storm (and maybe some other games) from a VM on unRAID to a laptop. Here's a video someone did showing how they got Heroes of the Storm to stream through Steam In Home Streaming (ignore the "to linux" part of the video name, if it works "to linux" it works to any OS).
There are other game streaming technologies you can look into as well, including Project Moonlight. In short, you should be able to make lots of games work through Steam In Home Streaming, even if they weren't actually purchased through Steam.
Thank you for your reply! I did actually find this and got Heroes working with in home streaming. I think I forgot that I could do this without having it on the unraid server and I was thinking we could make it be able to stream any game. Would a remote desktop work or this would be way too slow? Also, is there a way to get it to work when say at a friends house or something? I was also wanting to use it so I could run anything from my gaming PC like photoshop or something on my laptop and benefit from the gpu.