Change dimensions of CP 'preview' on stage after you've edited properties of a widget

Hey there - Is it possible to, once you've edited properties in the properties panel of your widget, resize the object on the captivate stage?
 
I'm making a wee URL button as the first thing I make. My default text on the url button is 'Button' which fits fine in my default width, 200px. But say I change that to, 'Click here to visit the knowledge base'; I can resize everything in the runtime to stretch my text field and the button background out (eg 500px), so all the text I put in fits - but on the Captivate stage it's still at 200px, and it just gets cut off. Publishes fine (full width), but the image on captivate stage is no longer representative so not ideal. I've tried doing the isReadyForStageSnapShot settings around my redraw, but it has no effect on the size of the button preview in CP. I've tried just setting the width manually too but it doesn't work, since when it goes to stage it can't see its whole width, it thinks its width is 200px not the 500px it would be at runtime.
 
Is there some function call to get Captivate to reassess the widget dimensions, ie. so Captivate knows now that the dimensions of my widget may have changed after I leave properties, and takes a new snapshot of the new size, if any? (ie. in my example, makes the button on CP stage 500px wide so you can see it all). That would be pretty tidy.
 
If there isn't, could this workaround work? Pass my new width and height variables through as properties of the widget, then, when enterStage() runs, just set 'width = properties.newWidth' before I take a snapshot?
 
Thanks heaps :) I am hoping that makes sense, haha.