GOOGLE DISK SAVES
Saves[drive.google.com]

Folder you need is here C:\Users\USERNAME\AppData\LocalLow\CDProjektRED\Thronebreaker\SaveData


1. To get last chest, open it right after you load.
2. To get last weapon, go to ? mark near gate, finish fight(you can skip it if it's lost) and spare the smith. He'll give you last weapon.
3. Take last letter and just read it.

Saves are not mine, all Thanks to SallyBons on CDproject forum.