A while back I mused to the mailing list:

> Registers for setting line length, page offset, page
> length, and vertical spacing trickled into the various macro packages in
> an inconsistent way over the years.
>
> One of the post-1.23 projects I have in mind is to complete the set for
> all macro packages and teach nroff about them so I can do something
> highly satisfying: give nroff an option to auto-size output to the
> terminal dimensions.

I foresee a couple of orthogonal dimensions of configuration here.

1.  Does the user want to simulate an infinite page length?

2.  Should the line length be set to "eat up" the entire terminal width, or set a large page offset so as to center the document in the terminal window?

We also might have to pretend that the terminal height is one line shorter than it actually is, to accommodate the prompt line used by pagers.  That might be a 3rd axis of configuration.