I have grown tenebrosas from 2" pot (tiny seedlings) to BS in 2-3 years (granted, in a greenhouse). They can bloom surprisingly small, so I don't think you have more than 2 years to go.
__________________ Kim (Fair Orchids)
Founder of SPCOP (Society to Prevention of Cruelty to Orchid People), with the goal of barring the taxonomists from tinkering with established genera!
I am neither a 'lumper' nor a 'splitter', but I refuse to re-write millions of labels.