Well if you want other quality games to occupy your time between each release here are a few
Deluca Family
Summer's gone
Leap of Faith ( has a superb opening chapter )
City of Broken Dreamers
The Last Call
These are just some of the ones i keep an eye out for but you can ofc find many more but the ones i named here are extremely polished releases
I personally think it will be around 12 - 14 episodes but that's just conjecture on my part. If we look at the various plots that are likely to be explored such as
1. Who is spreading the rumours about the HOTs and their "free" tuition
2. Who is responsible for the blackmail attempts on Chad and Dawe
3. Who is pulling Quinn's strings from behind the shadows cause contrary to popular belief she is NOT the antagonist i am sure of that now
4. What are Jill's plans regarding that campaign she wishes to start
5. What does tybalt do to that poor melon
6. Who was responsible for leaking Cathy's pics on Rooster
7. How will Tommy react when he learns that you are doing his step sister
8. In ep 3 bella asks James ( her husband ) to forgive her while thinking to herself in the library , what did she really do
9. How will the MC , Josy and Maya go about solving the HOTs scavenger hunt
10. When will i get that threesome with camila and mona ( ehmm that's more for me )
You get the point.. there is a LOT of things going on here so i think around 4 - 5 seasons should be enough to give us closure and a complete and fulfilling story unless DPC decides to go the route of another dev called Daniels K and half asses the endings