Computer out of music room

Dukeassassin,
here are some ways of providing an ethernet port without having to cut holes in the wall or fish cable:
- Establish a wifi mesh network.  And then use rj45 port on mesh network gear to establish ethernet connection  for your main system.  Could consider wifi mesh extender that could be used with existing router. 
(estimated cost for hardware $150-$300)
- Utilize pair of powerline ethernet adaptors.  This is a relatively inexpensive option.  (less than $100 for hardware).
I myself was faced with the same problem when I got seriously into streaming back in 2014.  My Gateway (combo modem and router) is on my lower level.  My main rig is on the main level.  I went the powerline ethernet route back in 2014 which I'm still using.  I have been considering upgrading to a mesh network solution using a wifi mesh extender.  

Hello duke assassin!
If I was in your shoes I’d be looking at a Roon Nucleus to act as both your Roon Core and network player hooked up to your DAC of choice with a suitable USB Cable. My choice would be a Chord Qutest tethered to the Nucleus via Curious USB Cable. I would then install an SSD into the bay of the Nucleus. A 1 TB SSD should do it, but I’d put in a 2 TB SSD just to be safe and give you room for adding more albums. I can personally recommend the Nucleus, Qutest and Curious USB cable, as I have all 3 in my main rig today.
What’s nice about this is that both the Nucleus and Qutest are high quality small footprint items. For further upgrade you could consider linear power supplies for both the Nucleus and Qutest. You can check out my system in the Virtual Systems Section.   https://systems.audiogon.com/systems/8156