I think there may be an ESL problem here or just bad explanations.
I think we're at:
The OP wants to be able to use his main rig, but to do so in bed, on the couch, whatever. He doesnt want to simply stream to his TVs because thats often unproductive in the extreme for non-gaming tasks. I have to adjust websites constantly when im browsing on my HTPC and its annoying AF. Text can be super hard to read well, as well, unless you blow it up so big you cant have much of it on the screen.
Running HDMI cables all over the place to keep a standalone monitor connected to this main rig is... not an optimal solution. And wireless keyboard/mouse range might be a serious issue.
That leaves a few different ways to do this, IMO, that will actually work the way the OP wants:
Method 1
Get a small portable standalone monitor (preferably with speakers). Plug a Steamlink-capable device into said monitor (Google TV dongle (Walmart makes one under its ONN Brand that is the same hardware as the actual Google device and is half as much); FireTV, or AppleTV are the easiest). You can connect your keyboard/mouse to this dongle (usualy Bluetooth unless you want to deal with a USB hub). Youll need some kind of lap board for using it in bed, but i think this will be an issue with whatever solution you go with (you need something to set the keyboard and mouse on at the very least).
For "small standalone monitor" i mean something like this:
https://www.walmart.com/ip/UsedAZMKO...B&gclsrc=aw.ds
Not saying that one in particular, but there are many similar devices out there. Make sure you get one with the features you want.
You will, of course, have at least a powre cable running to the monitor, but i think this is going to be a requirement no matter what - any laptop or tablet you try to use is going to have to be powered anyway unless you want the battery to implode in 60 minutes anyway.
This will get you the most "computer like" experience. You can just exit Big Picture Mode and be using the host computer as if you were sitting at it, and itll be big enough to read easily without having to jack up the text size or anything.
This method's requirements will be: Monitor, Streaming Dongle, Compatible Mouse/Keyboard (or controller), and a lapboard of some kind to use it in bed.
Method 2
Low to midrange Laptop + Steam In Home Streaming
As far as my research today has showed me, Steam In-Home Streaming works exactly like Steamink does, but it is from compter-to-computer that are both running Steam. It even uses the same interface, so, again, once you start Streaming, you simply exit Big Picture Mode and then youll be using your main rig at the desktop.
This would be very "computer like" as well, and has the benefit of having a keyboard built into it. Probably stilll need a lapboard of some kind though if you want to use a mouse instead of the trackpad.
You could also do this with a decent tablet. (Any tablet that can run the Steamlink app). Just.. use Steamlink, exit big picture, etc. Then you could get a keyboard case or whatever, but youll still need a lap board for a mouse.
Method 2B
Laptop or Tablet and some kind of Remote Desktop software.
Problem with this is that a lot of RDP clients dont do more than 30fps, wont handle DHCP content, etc. The ones that have more fidelity and capabilities cost a lot and often require a subscription.
This would be sub-optimal, IMO.
Similarly, the software that lets you just use a tablet as a second display doesnt support high framerates or a lot of content. Even Apple's Sidecar is limited in this way.
Method 3
Run cables everywhere. Get a long HDMI cable, USB cables, etc. Use a standalone monitor (like the small ones i mentioned above).
Pros are it will be a hardwire connection and not running through any remote anything.
Cons are cables everywhere.
TLDR
For the
easiest solution, i'd say a low-midrange laptop and In Home Streaming is the easiest one-stop shop. You might get stuck with a crappy screen if you go too cheap, but it is what it is.
I suppose you could get a decent Chromebook for this purpose (itll run the Android Steamlink app), and if you really want the tablet experience you can get a convertible or detachable. Ive used Steamlink through my HP Chromebook X2 11 and it works just fine.
FWIW, i wouldn't recommend that device (HP Charges too damn much for it - almost twice as much as the IDENTICALY spec'ed Lenovo Duet 5 - and the Duet 5 is actually slightly larger and has a better screen) - i only use it because i wanted something smaller than the Duet 5 and Lenovo hadn't released the newer Duet 3 yet. (The new Duet 3 is also a great choice as it is almost identically spec'ed and only ~320$ and is the smaller 11" size). If Best Buy hadn't put them on steep sale (got it for less than 300) i'd have waited for the Duet 3.
But really, any decent Chromebook would work fine (and there will be a native Steam app for Chromebooks soon, i think you can use the beta right now if you sign up). Similarly, any not-shit Windows laptop should be fine (stay away from dual-cores, low RAM, etc) but anything with 8GB of RAM and a decent quad core CPU should be more than enough.