The German version of FoV is out, but other releases are planned for mid October.
FoV concludes the story of the dragon slayer, so isn't a cliffhanger. Lar stated in another topic "For what it's worth - people who see the ending of Flames Of Vengeance smile".
On the other hand, a Divinity 3 is at least planned, so you're probably not going to completely wipe out all evil and usher in a golden age of peace.
The real Zandalor believed it was necessary to revive Ygerna, so it should be possible to convince a memory of him, as well (assuming it was complex enough to think rationally). Actually, even just convincing them that they were memories should be enough to stop the execution (similar to the dialog options you could take with the skeleton smith in Lovis' tower, or the existential skeletons in Divine Divinity).
There could even have been a point where you question the strategy of resurrecting Ygerna, but that would be enough of a break in the recurring memory to have the same effect as stopping the execution.
At some point during development, someone from Larian stated that there were no dialog changes based on the gender of the character, since the amount of text already in the game was fairly large. I don't know if publishers have some kind of limit, but the cost of localization, etc, does go up with the word count. Unfortunately, the mass market appeal goes down with the word count.
Even so, it would have been nice to have a couple different approaches for the end section, even if they all ended up with the same result.
