Jespersgaard: The only quest which you have to complete before venturing there is "The Warble of a Smitten Knight". It should also be noted that you will not be able to access your stash for quite awhile, so you should pick your endgame gear at this point. Everything will be accessible once you have finished the main-quest.
From what you say it would appear that I am nearing the end of Blood and Wine.
I still have many question mark places on the map to investigate.
All the manuscripts for the Witcher gear are about 10 levels lower than me so there is no need for
me to continue with Witcher gear hunts.