So, question about Illaoi.

So, I want to get Illaoi the day she releases (7100 IP, right?), though I also want to buy some new champions to have a bit of fun until she releases. Based on Riot's history, how long will it be for the PBE patch to go to live (she's in that patch)? Is she available on the first day of the patch?

I have 8026 IP right now. If I buy a 6300 champ today, would I be able to have the IP for her (I play 5-10 games a day, more if I don't work or have early hours)?