Dandelion does not deal with Geralt’s death well at all. On this blog, I consider the games to be almost as canon as the books, so there’s a five year time span between Geralt’s death in Lady of the Lake and his return in Witcher 1.
In a few short weeks, Dandelion lost everything: the Hansa, Geralt, Ciri, Annarietta, he was kicked out of a country that he had at one point planned to spend the rest of his life in (it wasn’t a good plan, but it was a plan).
But he considers himself to be Geralt’s best friend as well as his biographer, so he thinks it’s his duty to continue the Witcher’s legacy, even if it hurts him to do so. He tells his story, even though he has to get drunk before he can talk about him.
By the time of their reunion in The Witcher, Dandelion is the world’s best functional alcoholic. The fact that Geralt doesn’t remember him only makes it worse, every time he’s forced to remind Geralt of something or tell him about something he was there for, he has to drink.
The quest in Witcher 1 where Dandelion sends Geralt after his lute: he has to get drunk before telling Geralt where he can find the lute, but what actually upsets him is the fact that he has to explain WHY Geralt should go get the lute. Because the old Geralt wouldn’t have needed an explanation, he would have just done as he’d asked (after a bit of teasing, of course).
He also put Geralt on a pedestal (in song and his mind), so there are times when he’s just drunk enough to not be able to separate the ballads he’s created from the truth.
His alcoholism is something that he continues to struggle with off and on for many years, not truly being able to manage it until The Wild Hunt, when he settles down (a bit) with his Cabaret.
When threading with Geralt: Dandelion won’t easily admit to his alcoholism, but he’s certainly not subtle about it. If called on it, he will try to deny it, and certainly isn’t willing to tell the Witcher what caused it.