A free mod for Witcher 3, by ThatSpartacusGuy.

This is a great mod to make sure your character is not restricted by his or her carrying capacity. It allows you to carry up to 9,000 weight on your back without any restrictions. The weight is added to your character’s attributes and does not affect the way you move or attack. It works with all of the existing saddlebags in-game, including the ones from the expansion packs. It works on both the PC and mobile versions of the game.

The main advantage of this mod is that it allows you to equip any of the existing saddlebags in the game and get the benefits of the weight added to your character.