I don't think anyone has come up with a way to easily resize a widget with unknown structure. Depending on the components of the widget it may not even be possible to resize, on the fly.
So, it is difficult to do "automatically", but if you are willing to spend a little time in DXBuilder, you can select the objects and alter their size one at a time there, and repositioning as well. This would be no problem for basic widgets, but for more complex widgets it might be even easier to just "re-skin" them, using images and sizes appropriate for your needs.
That's one of the great things about DX is that a user can tweak such things themselves.
I see in another thread you asked about an MP3 player in particular. My SSMP has some large buttons, if that is helpful.
Single Switch Media Player