I'm not talking about just regular quests. End game or in this case end-dlc choices usually stick.
in this case I guess.
but huge things at the end of games or DLC usually happen regardless of what other choices you made
you always kill Alduin in Skyrim, and help the Brotherhood of Steel in Broken Steel
I'm pretty sure you always defeat whoever in the Knights of the Nine
just saying that there aren't usually choices that end up affecting the rest of gameplay
at least nothing as huge as the sun disappearing