You can go with portable mouse/keyboard and dock/usb-c-hdmi cable to any place and plug it into a hotel TV and be setup on your portable linux machine that can also...game :)
But I hadn't thought of this use case, so if it could handle it, it would be a game-changer.
My dock is more less a "no name" picked in store to try it out.
Also it has option to stream games rendered from your PC so you can play titles like CP2077 on steam deck rendered from your desktop if you feels so.
Things to be weary of:
1. Valve took the same tradeoff Nintendo took with a Switch. As a result, driving higher res displays (4k) works until it fails, badly. The increased processor / memory strain finds lots crashing edge cases.
2. Dock / un-dock has the standard set of headaches, the most annoying which is random pieces of software fixating on hardware that no longer exists when you un-dock (resolution changes, keyboard vs. on-screen, fallback to trackpads from missing mouse, ghost ethernet connections, sound headaches). This is endemic on the games side; random game + its proton shim + SteamOS doesn't like inputs changing. You will occasionally need a full reboot to fix issues.
3. It's a Linux. Torvalds is right then Valve is the best hope of "Linux on the Desktop" but the current frankensystem isn't there yet, and using any ports (or bluetooth) will expose you to a lack of friendliness not found on consoles or even (eww) Windows.