Adding wired connection across the house

Agree wired is the way to go.

If handy, go ahead and purchase online 300ft run, hook it up and see if it meets specs desired.

Quick search on inter webs has big online retail site with bulk CAT8.. A bit pricey and would need to terminate the connectors but offers plenty of bandwidth. CAT 7 supposedly is good for long runs as well. You may be able to get away with less run to a switch and then out to the end user as alternative.

 Hope this helps.

 Thanks and good luck.

They stated this:

"Stretching network cable across floors, halls, etc. doesn’t seem like a good solution."

@user_78a3a1 

You may want to consider hiring a local low voltage electrician to wall fish and hide the ethernet wiring for you.

MoCA adapters may also be a solution for you if your employers will allow them. You can Google them for more details / info.