Ok, a few more ideas for you:
1) borrow a streamer from your dealer as well as the 200 and get them to set it up so that it works with your NAS
2) bite the bullet and copy a few music files to your laptop and download a s/w music player onto your Laptop to play via USB to the 200. I'm an Apple user and can't really advise on what simple player to use on a PC but you could start a free trial of Audirvana+ Which is easy to install and works well. You can then delete all the s/w and music when your demo is complete
1) borrow a streamer from your dealer as well as the 200 and get them to set it up so that it works with your NAS
2) bite the bullet and copy a few music files to your laptop and download a s/w music player onto your Laptop to play via USB to the 200. I'm an Apple user and can't really advise on what simple player to use on a PC but you could start a free trial of Audirvana+ Which is easy to install and works well. You can then delete all the s/w and music when your demo is complete
IMac macOS 10.15.3 (no link to Devialet ) / MacBook Pro Retina OS X 10.14.4 / Linn LP12 / Devialet 200 / Wilson Benesch Discovery.
Qobuz Desktop Latest Version / Audirvana 3.2.18 / Audirvana Remote / iTunes 12.9 / AIR 3.0.4 / Wi-Fi / FW 8.1.0 / SAM 50%
Cambridge, UK (Updated 27th February, 2020)