The following solutions won't break long URLs more intelligently but may be useful alternatives. You can use (setq word-wrap t). It will allow line breaking at any space or tab character but without visual-line-mode. See C-h v word-wrap. In this case, maximum character length, as hoped in your message above, is the width of the window. I typically make my windows narrower if I want fewer character columns per line. On some occasions, I have used Olivetti mode to enforce a better reading experience but with wider windows.
The following solutions won't break long URLs more intelligently but may be useful alternatives. You can use
(setq word-wrap t). It will allow line breaking at any space or tab character but without visual-line-mode. SeeC-h v word-wrap. In this case, maximum character length, as hoped in your message above, is the width of the window. I typically make my windows narrower if I want fewer character columns per line. On some occasions, I have used Olivetti mode to enforce a better reading experience but with wider windows.