Have you looked into Moonlight? Nvidia is sunsetting GeForce Experience which would be a convenient streaming server, but Sunshine seems to be almost on par now, latency wise. So you‘d run Sunshine on your host machine, and Moonlight on the Steam Deck. I’ve seen people report a minimal input lag of just 1 frame @ 4k60 (with most recent Sunshine versions, there was a big leap recently) but haven’t tried it myself yet.
One big upside of Sunshine is that you can log into your host user remotely. So you could wake up the host with WoL and do the rest on the Deck.
Okay I've tried to use Moonlight today. It appears much more broken than Steam Link. There is no working autostart (but there is a broken service option), audio doesn't work, credentials sometimes just break to the point that a fresh start is needed, there is no way to elegantly exit the app, and it doesn't add the ability to unlock the PC (in fact, it even is so fragile that it requires a restart of the host program if the computer's primary display has turned off).
The options are nice and it sounds great on paper, but Steam Link is a better solution right now.
Moonlight only supports Xbox controllers or making a different controller (like a PS5 controller) appear to Windows to be an Xbox controller. You can't use a PS5 controller natively, instead windows sees the ps5 controller as an Xbox 360 controller.
It's fine for most cases but not for motion controls.
Not GP, but I use virtualhere to forward my steam controller over LAN to my desktop. Moonlight handles controllers fine, but it's forwarding button presses, not forwarding the USB device. This rarely makes a difference unless you're using peripherals that need software.
One big upside of Sunshine is that you can log into your host user remotely. So you could wake up the host with WoL and do the rest on the Deck.