[Question] Any simple way of downscaling a complete file?

[otraupe]

I found no option for making a complete file/image smaller, e.g. from square 1024 to 512.

My workaround:

1. group all objects
2. shrink manually to below the desired size
3. down-size the canvas
4. at 1000% zoom manually stretch the group borders to align with the canvas borders

Would be great to have an option to re-size in pixels or percentage with or without preserving aspect ratio.