How can I extend a shower curtain to close a gap at the floor?

My shower curtains fall a little bit too short (like 4cm / couple of inches) and in consequence there is a lot of splash on the floor on the other side of the curtains. Sometimes, it's really wet.

I have to mention that I'm talking about a Finnish shower —I'm living in Finland 🇫🇮— so there is not shower tray. It's just the bathroom floor leaning a little bit so the water goes to the sink on the floor.

The curtains are held in place with a rod and of course the obvious solution would be lower the rod. However, we are renting and we've talked with the company owning the building and told us that there is no posible. I guess they don't want to make more holes in the wall.

On the below image you can see the kind of hooks the curtains have.

Wondering if anyone around here has a great solution for this problem or there is nothing I can do.

Thanks!

PS/ The ideal situation is to have the curtains at 1cm or 0.5cm so they are close enough, but they don't touch the floor. If the curtain is touching the floor, mold in the curtains it's going to develop sooner or later.