I would like to know if there are plans for DLCs and what would be their possible release dates.
Completed the game a year ago and now I'm seriously longing for more...

unlikely imo as there isn't really anywhere for the story to go

It doesn't have to have a story, it can be a simple sandbox for starters.
Or maybe the DLC can have its own story about some other group of survivors.
I mean Frostpunk has, like, five of them.