VSCode zen mode for deleted module only

I wonder if there is a VSCode extension or setting that can enable Zen Mode only for a selected module.
I work with very long files but sometimes it is hard to search/replace or jump to certain places of the code where the file is so large and I just need to work within a module.
I want to avoid extracting the modules into many files since it involves a lot of overhead maintenance.

Ideally, I could select a module, then click on zen mode which will open an editor with only that piece of code, but when exiting the zen mode, it will go back to the big file and have my updated code.