I am trying to create a roguelike using the Text widget.
I have figured out a few things, namely that I can set the size of the widget using width and height options and that I can find the pixel height or width of said widget. However, what I want to do is have the widget resizable (pack(expand="yes", fill="both")) but be able to refresh the displayed text on a resize. Is there a way to get the character dimensions when the widget is running without resorting to winfo_width() and math based on pixel dimensions of characters?
I've run into that exact same problem a couple times jaccarmac, and to my knowledge there is no way to find the width of a string of characters. Really the only way is to use the winfo_ commands: width, height, geometry. However, it kind of sounds like you just want to make sure that all of the text is displayed if you change the label and add more text. If that is the case, you don't have to worry about it. That should all be taken care of by the widgets themselves. If you don't see them expanding to show all of your label, that usually means one of the widgets containing that label is not set to expand (either using expand=YES with .pack, or columnconfigure(i, weight=1) for .grid). 
A final thought; in the pack arguments make sure it's YES, and not "yes". That uppercase YES is not a string, but a variable name defined by Tkinter.
Finding The Current Size Of A tkinter.Text Widget