Upsizing nested smartobjects

Hi all,
I have this project where I have a bunch of smart objects. All are actually Groups of other smart objects that essentially are vector graphics.
The project is fairly low res, and the time has come to upsize the total image.
When I tried to resize the smart obecjts (the main ones, the Groups of smart objects) it resulted in a pixelated image.
Opening a smart object like that results with the old small canvas. Which is the main reason for the pixelation.
I am trying to figure out a way to cope with a fair number of smart objects nested in each other, instead of going into each smart object and resizing its canvas, realigning the graphics and applying editing... phew any sane way out of this ?

Thanks!