I have simple dress like this


But it does this really bad-looking transformation during knee-bend.



I tried to use 


But it did not help. Is there some smart (automated) way how to fix it except manual weight map editing?
I tried to do it, but it is not easy to fix it and don't break anything else.
There would be useful some kind of cloth physics simulation that will auto adjust the weight map for all bones based on simulation to match natural fabric stretching. I don't want to use real-time cloth simulation inside of my game.

Hello, you have to jump into Skin Weight settings and play around in there to get the perfect fit for your needs. There are many tutorials online. Here is one that should help you. Just jump to the part where you start doing the painting.
87% of original size (was 576x708) - Click to enlarge87% of original size (was 576x708) - Click to enlarge

87% of original size (was 576x708) - Click to enlarge

Yes. I already tried that. I even fixed my issue, but then it started looking weird in a different pose. 
So I was just curious if there is already some smarter way how to do that. 
I probably need to wait a few more years with my little project :-) 

Hide body mesh under the dress in "troubled" areas (you are not going to get  it to perfection with weights anyway).
And when exporting check Delete Hidden Mesh.

You may hide the mesh under cloth Modify panel with "Hide Body Mesh Tool" button...
Or directly by editing body mesh, selecting faces and using Hide button (or with sculpt brush).

Yes. I'm using the Hide Body Mesh Tool, but it is not possible to hide under the bottom part of the dress.
I finally fine tune it for Full Bofy motion animation, it looks like this



Sadly not so good from inner side.

Bude when I use some dance animation when one legs go up and second down. I'm lost again

87% of original size (was 576x708) - Click to enlarge

This part of the leg is visible from the bottom when a character is standing normally, so it is not possible to hide the whole leg.

It is even possible to do that just by skin weight paint?

I expected that using software like CC will handle all that issue which must be handled in normal 3D tools like Blender..

Tight dresses/skirts is harder to weight paint to perfection.
You can do a better weight paint job there AFAICS though, but you also have to compromise as well.
It seems the dress mesh is way too close to the body.

Otherwise simulate it elsewhere (Blender, MD) and import sim as alembic (whole other story).