After thinking about it for not too long (and after cuddling in foetal position for some good 10 minutes realizing how consensus-less fanatics have provocked this abrupt awaken of a beutiful dream) by now I am cashing my BTC immediately.
I can see why it might seem like a good idea, but there if a potential to lose out doing it that way. Hodling in the event of a split means you get coins on both chains. Selling before the split means you have to buy back after the split and choose very carefully which chain you think has the best chance of survival. And if you take too long deciding, the fiat price may well recover to a level above the point that you panic sold.
It is obvious that you are not a (very experienced) trader (or not a trader at all)
Selling bitcoins before the split would be a wise decision any way you look at it. It is almost a certain that price will crash after the split (even if temporarily) or even before it (if it is really going to happen, due to insiders cashing out), so the risk is not worth it. If you don't know which camp to stick to, you can buy back both coins at cheaper price, and thus you would be better off overall than if you decided just to hold. I guess I won't have to explain where exactly your logic fails. It should be straightforward