How to make widgets span 5 cells

Previously I've used the ADW launcher but have found every phone I've had become unmanageably slow over time. I've never been able to identify the problem but this time I'm trying to leave as many things stock as I can bear, starting with the launcher.

The default launches seems palatable enough but I can't workout how to resize widgets to fill the width of the screen.
Two of my favorite widgets to have on the home screen are "Fancy Widgets" (a clock/weather widget) and "Agenda Widget" (a calendar widget). Both these programs have several different sized widgets available but neither have widgets that are 5 cells wide. Is there a way to stretch the widget in the default launcher like one can in ADW?

Attached is an example of what my home screen currently looks like.

Thanks,
Slarti.


P.S.
I hope I'm asking this in the correct place.
(I wasn't able to find a Q&A section for G3 themes)

Uh, I've found that after releasing the agenda widget when dragging resize grippers become available on the corners.

This works perfectly to resize Agenda Widget to a 5x2 box.
Unfortunatly this doesn't work for Fancy Widgets.