Growth depends on the snake too, I fed my jungle male the same as my other boas and he just spurted in size so much more than my others. I got an albino female last year who is now only slightly larger than my Hog female who I got this year. Just depends on the snake, but usually at/around their second birthday is when I need to move into vivs from their tubs.
I don't know the size of that tub but I'd recommend at least a 4' viv, unless you get a Hog that gets exceptionally large then a 6'.