You could add the Editor Guidelines extension into Visual Studio:
https://marketplace.visualstudio.com/items?itemName=PaulHarrington.EditorGuidelines
I find it helpful to visually limit the length of lines of code, but it's not an automatic enforcement.
Answer from Ben Wesson on Stack Overflow[Suggest] Supporting max_line_length in editorconfig
.net - C# coding convention for line width - Stack Overflow
How to auto enforce code styles like 1 dot per line for chained methods?
Roslyn formatter should offer an option to enforce a maximum number of columns per line
If I went with "what fits", without much thought other than that, I would be cramming 60 lines into a function at 260 characters per line, and could still argue that "it all fits on my screen". It does, and I'm not using a ridiculously small sized font either. (9 pt Courier New, 24-inch widescreen monitor at 1920x1200, with basically the whole screen real estate devoted to code; the solution explorer, code definition window, output window, error list and so on are on my second monitor.)
Everyone is going to have their own opinion, and personally I think 80 character line widths are a bit off in the other direction these days, but depending on exactly what it is about, I try to keep myself under 100-120 characters per line, including indentation. If it gets much longer than that, there's probably parts in it that can easily be broken out and put on separate lines in ways that improve readability.
Because that is what it really is about. Readability. I don't really care if you use 60 characters per line or 200, but when I have to work with your code, it had better be easy to read and easy to tell at a glance what it does.
Also, try to chunk your code in ways that will provide meaningful diffs that are, again, easy to read. That's another rule of thumb I try to stick to; if I compare two sets of files, I want to see the changes that actually matter, not kilometer-long lines where the only difference is a single character change (which may very well be a very valid change, but is difficult to find in such a behemoth).
I have two monitors, one is 26' and the other 22'. I use the smaller one to place utility windows as File Structure, Class view, Code definition, Object browser, To-do Explorer, Output, Error list, Pending changes (Ankh plug in) and so on. I leave the main window just for code and the project browser, so I told ReSharper set my line width to 160 characters (just in case I'd need some line to be that long). Normally I won't exceed 120 characters which is the length I feel most comfortable with. I'd feel really dumb if I had to work on this monitor with fewer than that.
The 80 characters per line made sense back in the day, when it was the standard width for monitors in text mode.
Csharpier can't do it. Dotnet format can't do it.
Being spoiled by the ease of use of formatters like black/gofmt/clang-format I wonder if there's finally a solution for C# yet? dotnet format seems ok but doesn't do line breaking or spurious empty line removal (please correct me if I'm wrong)? CSharpier does do the latter but doesn't do things like converting single-line properties/functions to expression bodies as dotnet format does nor enforcing naming rules, ordering of things within a class? And clang-format/uncrustify/astyle just don't seem to know C# enough to even get close.
How do others do this? Some magic tool I don't know about? Just live with it like in the old days?