Clone painting with Blender 2.80

Clone painting has been a pain for me and I only got it right occasionally. With Blender 2.80 I am stuck again (or should I say don’t know where to begin) as Blender Internal is no more.
What I have is an object that is unwrapped in a matter, that allows me to use an image texture. In the end I have a PBR material with an image texture, a normal map and an image for the roughness and maybe one for metalness.
What I want to use in my model is a different UV unwrapping. In the past I achieved this with clone painting.

Is there a better way to get from an image that works with UV unwrapping A to an image with UV unwrapping B?
How to do this in Blender 2.80?

I thought of baking, even tried out the described procedures. The UV map that is used in the baked image is the same as the one I baked from. At least this is the result I get in 2.80, which might be a bug.
The only way this would help me is if I made the baked to image the size of the UV map.

make the texture the size of the UV? I have no idea what you mean. UV maps don’t have a size, they have coordinates based on a 0-1 x 0-1 scale. If all you’re trying to do is resize the textures, do that in the compositor.

If you’re trying to go from one UV layout to another: