We are targeting 1 - 2 months internally. I must stress though this is subject to change. Currently we believe the remaining work is relatively straightforward, but it will depend quite a lot on how our testing goes.
Regardless are really excited we will be able to bring the missions inside of the open world experience for Olympus and styx. I think styx is underrated, and this I think will really bring that beautiful map out.
We will include additional estimates and updates in each of our weekly update posts as we proceed with the work.