Does anyone even know how much content the new season covers? We don’t even know how many episodes there are. Aside from the scriptwriter, at least.
The first season covered six-and-a-bit volumes, so a second season of the same length would probably finish somewhere in volume thirteen. Give or take a bit depending on how they have to adjust the pacing to make good television.
I don’t think there’s a good stopping point for 12 episodes, so I hope it’s at least 24 (though given the production trouble - maybe a split cour setup with a gap in the middle). My guess is in that case we’re going up to the end of volume 12.
So volume 7 is kind of a lot of side quests, we’ll probably get some of them in the series (especially The Hero Of The South), but I imagine some of them will get cut for time. We do see others in the trailer, so we know at least some of them are in!
After that there’s 3 major arcs between where the anime ended and the current volume:
The next big arc is the Golden City which is volume 8-11 which there will be war if it doesn’t make it in.
After that there is the Goddess’ Monument arc. In the manga it’s shorter than Golden Land and is basically volume 12. It’s also a fan favourite, so I could see them wanting to lengthen it in the anime.
Then there’s a few more side quests, and finally the current (not yet complete!) Foundation Festival arc across volume 13-15. I don’t think there’s space to start the Foundation Festival, but they might try put the side quests in? That said, if they want the anime season to end on a conclusion, they’d probably want to align with the end of one of the big arcs.
Thanks for the detective work everyone 
The club just finished volume 8 if anyone would like to stop by for a volume level chat 
And stay tuned for Volume 9 starting on January 23rd 
And a shout out to @trunklayer reading Frieren at a very consistent chapter a day pace 
So apparently the cour is going to be 10 episodes, and their big tease was the voice actor for The Hero Of the South so I retract my previous speculation and guess we’re just going to stretch out volumes 7/8 based on that.