Moving Objects After Resizing Stage

create a new fla with the desired stage size

copy all the layers from your large staged fla

paste into the new fla

if you lucky, you won't have to reposition to much.

Hi.

You can also resize the stage and then use the Edit Multiple Frames toggle at the top of the Timeline panel to select all content from all frames at once and move it to the required position.

Regards,

JC

I think your best options would be:

Use Adobe Animate's virtual camera to zoom in on your animation so that it covers the entire viewing area.

Or to copy all your main timeline layers into a new symbol which you can then scale up to cover the entire stage area.

Both of these methods avoid the need to adjust animations so long as the animations' aspect ratio doesn't need to be changed.

Other methods like resizing the stage via the project properties tends to require some animation fixes from what experienced in the past.