It’s just speculation, but it sounds like you’re using a pen display (graphics-tablet with display), right?
Then you also have the possibility to display only the canvas on the pen display, and to place the Dockers floating freely on the laptop / PC display, because these are movable. This way you create more space for the canvas.
Another nice thing, I find the before mentioned Krita UI Redesign Plugin described here.
I like this plugin so much, because even in canvas only mode, which is accessible with the tab key, you have the tools you have just enlarged available and the Tool Options Docker as well, and can show and hide them at will, you no longer have to leave the canvas to access it. So, no longer back and forth!
If you also install the plugin Kanvas Buddy or alternatively the plugin Pie Menu, or both, then you get a very comfortable solution to almost not need the disturbing Dockers, so you can stay mostly in canvas only mode and use all the space your display offers!
These two plugins can be shown via shortcut on the canvas, and they provide you with different tools, these tools you can choose very freely with Pie Menu and with Kanvas Buddy you have a configurable selection that you can extend with little scripting or programming knowledge (I myself love Kanvas Buddy).
This is the GitHub project page of the Krita UI redesign plugin, I’m using the 0.5 alpha version direct download, if an alpha is too insecure you could use version 0.2 download with this instead.
Kanvas Buddy’s version patched by @Halcyoen for Krita 5.x can be downloaded from his GitHub project page, here is the direct download link, in this ZIP file you will find the file “kb-0-5-unofficial.zip” where the plugin is located, it’s handled a bit unfortunate 
but works fine.
And this is the project page of Pie Menu, and this is the direct download link of the plugin, and here you don’t have to search for any file in the zip.
The easiest way to install plugins in Krita is to go to “Tools” >> “Scripts” >> “Import Python Plugin from File…”, then in the dialog that opens, specify the path to the plugin (the ZIP files you just downloaded) and confirm it, confirm the next dialog box as well, then restart Krita and then, depending on the plugin, set up the plugin to your liking.
But even if you don’t use a display graphics tablet, these three plugins are definitely worth a look, even with a “normal” graphics tablet or just the mouse together. For some users they should even be worth their weight in gold, I once read somewhere.
Michelist