Over the next few hours we'll be bringing down ranked on PBE to start testing the 2016 season transition. When ranked comes back up, 2015 ranked data will be archived and new champion select with dynamic queues (meaning you can enter queue with 1-5 players in ranked) will be enabled. Remember, tier restrictions remain in place, so even five players can only span two tiers in rank.
We'll be disabling all other queues over the weekend to collect enough data to be confident in the changes.
Placement on PBE only requires 1 game to allow for faster testing. This causes some known visual errors with the seeding text on the profile page. If you spot any other issues let us know and thanks for the help!