The Witcher 3: Blood and Wine is the 2nd expansion for the base game, and it takes Geralt to an entirely new region, Toussaint! However, to start the expansion, you're going to need to reach a certain point in the base game's main story and reach a high enough level, as great challenges await. Below, you'll find a full walkthrough of Envoys, Wineboys to start the expansion and learn of the choices you can make!
How to Start the Blood and Wine Expansion in The Witcher 3
In order to get the first quest for Blood and Wine, you'll have to progress deep enough into the base game until you complete "A Poet Under Pressure", which is in Novigrad. Afterward, you can explore the notice boards of Velen to find the contract titled "Appeal to Sir Geralt of Rivia, the Bridge his Crest." Inspect this contract, and you will get the "Envoys, Wineboys" quest for the Blood and Wine expansion.
You will now need to travel to Stonecutter's Settlement, which is to the west of Oxenfurt. However, make sure you're at least Level 32, as the recommended Level for this quest (and most of Blood and Wine) is 34+. Once you arrive, you can speak with two knights from Toussaint, Palmerin de Launfal and Milton de Peyrac-Peyran.
Should You Help Defeat the Bandits in Envoys, Wineboys?
The knights will tell you that they have a duty to protect the village from bandits, and they ask you to wait inside their hut while they deal with these marauders. Geralt has two options:
Lemme help you with the bandits. Geralt will fight a bunch of bandits with the knights, but earns no reward.
Get rid of these bandits, worse ones'll come in to replace 'em. Geralt waits for the knights to defeat the bandits by themselves.
Your decision here does not matter, and if you do decide to help with the bandits, your dialogue to the bandits themselves also does not matter, as they will fight regardless. Either way, the village is not too pleased about the fighting, and the knights (along with Geralt) return to the hut to discuss the meaning of their visit.
Should You Accept the Toussaint Contract in Envoys, Wineboys?
The knights will give Geralt a contract to hunt a Beast in Toussaint, as direct orders from the Duchess herself. Geralt is then faced with two choices:
I'll take the contract. Geralt and the knights set off for Toussaint immediately.
This contract – need to think about it. Geralt leaves but can return to Stonecutter's Settlement at any time to go to Toussaint.
If you're ready to start the Blood and Wine expansion and leave Velen behind, then tell the knights that you're ready to accept the contract, and you can travel to Toussaint. This will immediately start the next mission, "The Beast of Toussaint".
Source: Game Rant