If you type a value, say 80 in your case and copy or cut it (get it into the clipbopard) then when you use the Text FX Edit function to “Wrap text To…” it will honor the value in the clipboard rather than 72. Unfortunately, this ruins some of the formatting, secifically tabbed elements…not cool.
I have resorted to using the Alt+Left Click and Drag column selection method to simply view given size, referencing a text bloc, a bunch of #'s, that have the desired length. None are optimal…