I did the same thing running fiber in my older house, and was virtually always able to find a premade within a reasonable number of feet of the length I needed.

I did the same thing running fiber in my older house, and was virtually always able to find a premade within a reasonable number of feet of the length I needed. Yeah, I had to widen a few holes to snake the connectors thru, but it wasn't horrible and all in places you don't see it. If it was new construction, I'd certain pay a few extra $$$ to have a pro do it, because I don't trust me to do a good enough job terminating fiber.