I think this game has some issues with the distribution of blacksmiths. It seems to rely on fast travel while I've tried to play the game using fast travel as little as possible.
For instance, on the east side of Velen there doesn't seem to be a single blacksmith south of Lindvale. I don't remember if there's one in the Nilfgaardian camp but there should be. There should at least have been one in Downwaren or maybe one of the little towns east of it.
The worst though is when essential gameplay elements like blacksmiths become temporarily unavailable during events. I came back from doing that quest on Undvik carrying a shitload of loot -- I was overweight, but thought it was fine because I could just sell or dismantle all of it at the armorer as soon as I got to Kaer Trolde, but one of the major side quests started when I got there and I had to walk around at slow speed throughout the whole quest. I know this is kind of a spoiler but I'm just gonna post this and highlight it for anyone still doing those two quests in the islands west of Ard Skellig: If you come back from those islands full of loot, stop over at Kaer Muire first (the big castle town on the southwest corner of Ard Skellig) to sell/dismantle that stuff. On top of that, so far the only journeyman blacksmith (sword forger) I've found in west Skellige is in Kaer Muire -- almost on the other side of the island from Kaer Trolde.
Things like this are what makes the big AAA publishers put a ton of anti-frustration features in their games that ultimately end up removing the sense of challenge though. BioWare or Ubisoft probably would've solved this problem in some blanket fashion like letting you craft anywhere or maybe removing inventory entirely like in Mass Effect 2. Instead developers just need to do a better job of balancing this stuff. Witcher 3 mostly does a great job in terms of designing the layout of its world so it feels fun to explore and traverse. There seems to be just the right frequency of secrets and extra things to find, but it all seems to be placed sensibly and organically. I almost never use fast travel and haven't gotten bored going from place... except when trying to reach blacksmiths.