Not sure if this is necessarily a "good" suggestion, but I'll toss it out anyways.

I'm assuming that when you "hand tweak the widths" that you're doing so on a Windows system that has Excel. Working off that assumption, here's one crazy (and maybe extreme) idea:

• Have your current script put the Excel file on a network share and not do the automated email.
• From a Windows system that has Excel installed and access to the network share from the previous step, have a script that goes opens the Excel file from that share and uses Win32::OLE to handle all of the autofit stuff. You should be able to use task scheduler to configure this script to run at a specific time each week.
• Then have yet a third script that would handle the emailing of the finalized Excel file.

If having a Windows box with Excel to handle the autofit stuff is not a viable solution for you, perhaps you can look into using OpenOffice or LibreOffice and automate the autofit through their API - similar to using Win32::OLE to automate Excel.

I'll admit my ideas probably are a bit crazy and extreme, but thought I'd toss them out in case it proves useful or might give someone an idea for a better solution.