■■■■, thank you! Not exactly you said, but there is a way you leaded me too.
After making rectangle 1024x1024 mm (for texture 1024x1024 px) and adding a texture as a material to it, its displayed like I want. After right-click - there is an option “make unique texture” - that makes a texture with size 1px:1mm scale, not 25x bigger as before.
After such operation I can use that new material wherever I want and it has a proper size.
Thanks alot!