Doesn't your editor support multiple files and global find?

(I'm not knocking your preferences, just wondering why you hold them if that makes sense).

The biggest problem with lots of stuff in big files is that I nearly always want to edit one place whilst flicking back forth to a couple of others. Even with an editor that supports multiple views within the same file, it is usually limited number of views (often only two) which doesn't cut it.

By putting stuff in small(er) files I can switch from one file to another for reference or editing and switch back to where I was in the first, cursor in place and just carry on.

The ability to save and restore whole sessions of files as a single command line option is invaluable. If only TP would remember where I was in each file it'd make me a happy bunny.

I use a global search to generate an index to the function, method or variable I am interested in and that allows me to flick between the relevant files easily.

In the end I guess it's down to how your habits have evolved, but I find huge monolithic files tedious and awkward to deal with.