How much does your ranked climb from preseason count into the next season?

Not sure why or how, but since the preseason ended and we got SoloQ back I suddenly started climbing like crazy. Maybe it had nothing to do with SoloQ, and that's just a random correlation, but that's the main thing that changed when season 6 ended. Oh and I started playing Taliyah jungle again for the lolz of it.

So I got from Gold 5/4 to Platinum 5, almost being in Plat 4, and tbh it would kinda suck to see that all go to waste with the new season.

But at the same time they said preseason ranked "kinda" counts? I mean, it kinda has to or they would have just disabled ranked during that time...